Esempio n. 1
0
/* Subroutine */ int chbev_(char *jobz, char *uplo, integer *n, integer *kd, 
	complex *ab, integer *ldab, real *w, complex *z__, integer *ldz, 
	complex *work, real *rwork, integer *info)
{
/*  -- LAPACK driver routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       June 30, 1999   


    Purpose   
    =======   

    CHBEV computes all the eigenvalues and, optionally, eigenvectors of   
    a complex Hermitian band matrix A.   

    Arguments   
    =========   

    JOBZ    (input) CHARACTER*1   
            = 'N':  Compute eigenvalues only;   
            = 'V':  Compute eigenvalues and eigenvectors.   

    UPLO    (input) CHARACTER*1   
            = 'U':  Upper triangle of A is stored;   
            = 'L':  Lower triangle of A is stored.   

    N       (input) INTEGER   
            The order of the matrix A.  N >= 0.   

    KD      (input) INTEGER   
            The number of superdiagonals of the matrix A if UPLO = 'U',   
            or the number of subdiagonals if UPLO = 'L'.  KD >= 0.   

    AB      (input/output) COMPLEX array, dimension (LDAB, N)   
            On entry, the upper or lower triangle of the Hermitian band   
            matrix A, stored in the first KD+1 rows of the array.  The   
            j-th column of A is stored in the j-th column of the array AB   
            as follows:   
            if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;   
            if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd).   

            On exit, AB is overwritten by values generated during the   
            reduction to tridiagonal form.  If UPLO = 'U', the first   
            superdiagonal and the diagonal of the tridiagonal matrix T   
            are returned in rows KD and KD+1 of AB, and if UPLO = 'L',   
            the diagonal and first subdiagonal of T are returned in the   
            first two rows of AB.   

    LDAB    (input) INTEGER   
            The leading dimension of the array AB.  LDAB >= KD + 1.   

    W       (output) REAL array, dimension (N)   
            If INFO = 0, the eigenvalues in ascending order.   

    Z       (output) COMPLEX array, dimension (LDZ, N)   
            If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal   
            eigenvectors of the matrix A, with the i-th column of Z   
            holding the eigenvector associated with W(i).   
            If JOBZ = 'N', then Z is not referenced.   

    LDZ     (input) INTEGER   
            The leading dimension of the array Z.  LDZ >= 1, and if   
            JOBZ = 'V', LDZ >= max(1,N).   

    WORK    (workspace) COMPLEX array, dimension (N)   

    RWORK   (workspace) REAL array, dimension (max(1,3*N-2))   

    INFO    (output) INTEGER   
            = 0:  successful exit.   
            < 0:  if INFO = -i, the i-th argument had an illegal value.   
            > 0:  if INFO = i, the algorithm failed to converge; i   
                  off-diagonal elements of an intermediate tridiagonal   
                  form did not converge to zero.   

    =====================================================================   


       Test the input parameters.   

       Parameter adjustments */
    /* Table of constant values */
    static real c_b11 = 1.f;
    static integer c__1 = 1;
    
    /* System generated locals */
    integer ab_dim1, ab_offset, z_dim1, z_offset, i__1;
    real r__1;
    /* Builtin functions */
    double sqrt(doublereal);
    /* Local variables */
    static integer inde;
    static real anrm;
    static integer imax;
    static real rmin, rmax, sigma;
    extern logical lsame_(char *, char *);
    static integer iinfo;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
    static logical lower, wantz;
    extern doublereal clanhb_(char *, char *, integer *, integer *, complex *,
	     integer *, real *);
    static integer iscale;
    extern /* Subroutine */ int clascl_(char *, integer *, integer *, real *, 
	    real *, integer *, integer *, complex *, integer *, integer *), chbtrd_(char *, char *, integer *, integer *, complex *, 
	    integer *, real *, real *, complex *, integer *, complex *, 
	    integer *);
    extern doublereal slamch_(char *);
    static real safmin;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    static real bignum;
    static integer indrwk;
    extern /* Subroutine */ int csteqr_(char *, integer *, real *, real *, 
	    complex *, integer *, real *, integer *), ssterf_(integer 
	    *, real *, real *, integer *);
    static real smlnum, eps;
#define z___subscr(a_1,a_2) (a_2)*z_dim1 + a_1
#define z___ref(a_1,a_2) z__[z___subscr(a_1,a_2)]
#define ab_subscr(a_1,a_2) (a_2)*ab_dim1 + a_1
#define ab_ref(a_1,a_2) ab[ab_subscr(a_1,a_2)]


    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1 * 1;
    ab -= ab_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1 * 1;
    z__ -= z_offset;
    --work;
    --rwork;

    /* Function Body */
    wantz = lsame_(jobz, "V");
    lower = lsame_(uplo, "L");

    *info = 0;
    if (! (wantz || lsame_(jobz, "N"))) {
	*info = -1;
    } else if (! (lower || lsame_(uplo, "U"))) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (*kd < 0) {
	*info = -4;
    } else if (*ldab < *kd + 1) {
	*info = -6;
    } else if (*ldz < 1 || wantz && *ldz < *n) {
	*info = -9;
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHBEV ", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*n == 0) {
	return 0;
    }

    if (*n == 1) {
	if (lower) {
	    i__1 = ab_subscr(1, 1);
	    w[1] = ab[i__1].r;
	} else {
	    i__1 = ab_subscr(*kd + 1, 1);
	    w[1] = ab[i__1].r;
	}
	if (wantz) {
	    i__1 = z___subscr(1, 1);
	    z__[i__1].r = 1.f, z__[i__1].i = 0.f;
	}
	return 0;
    }

/*     Get machine constants. */

    safmin = slamch_("Safe minimum");
    eps = slamch_("Precision");
    smlnum = safmin / eps;
    bignum = 1.f / smlnum;
    rmin = sqrt(smlnum);
    rmax = sqrt(bignum);

/*     Scale matrix to allowable range, if necessary. */

    anrm = clanhb_("M", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]);
    iscale = 0;
    if (anrm > 0.f && anrm < rmin) {
	iscale = 1;
	sigma = rmin / anrm;
    } else if (anrm > rmax) {
	iscale = 1;
	sigma = rmax / anrm;
    }
    if (iscale == 1) {
	if (lower) {
	    clascl_("B", kd, kd, &c_b11, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	} else {
	    clascl_("Q", kd, kd, &c_b11, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	}
    }

/*     Call CHBTRD to reduce Hermitian band matrix to tridiagonal form. */

    inde = 1;
    chbtrd_(jobz, uplo, n, kd, &ab[ab_offset], ldab, &w[1], &rwork[inde], &
	    z__[z_offset], ldz, &work[1], &iinfo);

/*     For eigenvalues only, call SSTERF.  For eigenvectors, call CSTEQR. */

    if (! wantz) {
	ssterf_(n, &w[1], &rwork[inde], info);
    } else {
	indrwk = inde + *n;
	csteqr_(jobz, n, &w[1], &rwork[inde], &z__[z_offset], ldz, &rwork[
		indrwk], info);
    }

/*     If matrix was scaled, then rescale eigenvalues appropriately. */

    if (iscale == 1) {
	if (*info == 0) {
	    imax = *n;
	} else {
	    imax = *info - 1;
	}
	r__1 = 1.f / sigma;
	sscal_(&imax, &r__1, &w[1], &c__1);
    }

    return 0;

/*     End of CHBEV */

} /* chbev_ */
Esempio n. 2
0
/* Subroutine */
int chbgvd_(char *jobz, char *uplo, integer *n, integer *ka, integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb, real *w, complex *z__, integer *ldz, complex *work, integer *lwork, real *rwork, integer *lrwork, integer *iwork, integer *liwork, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, bb_dim1, bb_offset, z_dim1, z_offset, i__1;
    /* Local variables */
    integer inde;
    char vect[1];
    integer llwk2;
    extern /* Subroutine */
    int cgemm_(char *, char *, integer *, integer *, integer *, complex *, complex *, integer *, complex *, integer *, complex *, complex *, integer *);
    extern logical lsame_(char *, char *);
    integer iinfo, lwmin;
    logical upper;
    integer llrwk;
    logical wantz;
    integer indwk2;
    extern /* Subroutine */
    int cstedc_(char *, integer *, real *, real *, complex *, integer *, complex *, integer *, real *, integer *, integer *, integer *, integer *), chbtrd_(char *, char *, integer *, integer *, complex *, integer *, real *, real *, complex *, integer *, complex *, integer *), chbgst_(char *, char *, integer *, integer *, integer *, complex * , integer *, complex *, integer *, complex *, integer *, complex * , real *, integer *), clacpy_(char *, integer *, integer *, complex *, integer *, complex *, integer *), xerbla_(char *, integer *), cpbstf_(char *, integer *, integer *, complex *, integer *, integer *);
    integer indwrk, liwmin;
    extern /* Subroutine */
    int ssterf_(integer *, real *, real *, integer *);
    integer lrwmin;
    logical lquery;
    /* -- LAPACK driver routine (version 3.4.0) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* November 2011 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Parameters .. */
    /* .. */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Test the input parameters. */
    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    bb_dim1 = *ldbb;
    bb_offset = 1 + bb_dim1;
    bb -= bb_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --work;
    --rwork;
    --iwork;
    /* Function Body */
    wantz = lsame_(jobz, "V");
    upper = lsame_(uplo, "U");
    lquery = *lwork == -1 || *lrwork == -1 || *liwork == -1;
    *info = 0;
    if (*n <= 1)
    {
        lwmin = *n + 1;
        lrwmin = *n + 1;
        liwmin = 1;
    }
    else if (wantz)
    {
        /* Computing 2nd power */
        i__1 = *n;
        lwmin = i__1 * i__1 << 1;
        /* Computing 2nd power */
        i__1 = *n;
        lrwmin = *n * 5 + 1 + (i__1 * i__1 << 1);
        liwmin = *n * 5 + 3;
    }
    else
    {
        lwmin = *n;
        lrwmin = *n;
        liwmin = 1;
    }
    if (! (wantz || lsame_(jobz, "N")))
    {
        *info = -1;
    }
    else if (! (upper || lsame_(uplo, "L")))
    {
        *info = -2;
    }
    else if (*n < 0)
    {
        *info = -3;
    }
    else if (*ka < 0)
    {
        *info = -4;
    }
    else if (*kb < 0 || *kb > *ka)
    {
        *info = -5;
    }
    else if (*ldab < *ka + 1)
    {
        *info = -7;
    }
    else if (*ldbb < *kb + 1)
    {
        *info = -9;
    }
    else if (*ldz < 1 || wantz && *ldz < *n)
    {
        *info = -12;
    }
    if (*info == 0)
    {
        work[1].r = (real) lwmin;
        work[1].i = 0.f; // , expr subst
        rwork[1] = (real) lrwmin;
        iwork[1] = liwmin;
        if (*lwork < lwmin && ! lquery)
        {
            *info = -14;
        }
        else if (*lrwork < lrwmin && ! lquery)
        {
            *info = -16;
        }
        else if (*liwork < liwmin && ! lquery)
        {
            *info = -18;
        }
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CHBGVD", &i__1);
        return 0;
    }
    else if (lquery)
    {
        return 0;
    }
    /* Quick return if possible */
    if (*n == 0)
    {
        return 0;
    }
    /* Form a split Cholesky factorization of B. */
    cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
    if (*info != 0)
    {
        *info = *n + *info;
        return 0;
    }
    /* Transform problem to standard eigenvalue problem. */
    inde = 1;
    indwrk = inde + *n;
    indwk2 = *n * *n + 1;
    llwk2 = *lwork - indwk2 + 2;
    llrwk = *lrwork - indwrk + 2;
    chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb, &z__[z_offset], ldz, &work[1], &rwork[indwrk], &iinfo);
    /* Reduce Hermitian band matrix to tridiagonal form. */
    if (wantz)
    {
        *(unsigned char *)vect = 'U';
    }
    else
    {
        *(unsigned char *)vect = 'N';
    }
    chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &w[1], &rwork[inde], & z__[z_offset], ldz, &work[1], &iinfo);
    /* For eigenvalues only, call SSTERF. For eigenvectors, call CSTEDC. */
    if (! wantz)
    {
        ssterf_(n, &w[1], &rwork[inde], info);
    }
    else
    {
        cstedc_("I", n, &w[1], &rwork[inde], &work[1], n, &work[indwk2], & llwk2, &rwork[indwrk], &llrwk, &iwork[1], liwork, info);
        cgemm_("N", "N", n, n, n, &c_b1, &z__[z_offset], ldz, &work[1], n, & c_b2, &work[indwk2], n);
        clacpy_("A", n, n, &work[indwk2], n, &z__[z_offset], ldz);
    }
    work[1].r = (real) lwmin;
    work[1].i = 0.f; // , expr subst
    rwork[1] = (real) lrwmin;
    iwork[1] = liwmin;
    return 0;
    /* End of CHBGVD */
}
Esempio n. 3
0
/* Subroutine */
int chbgv_(char *jobz, char *uplo, integer *n, integer *ka, integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb, real *w, complex *z__, integer *ldz, complex *work, real *rwork, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, bb_dim1, bb_offset, z_dim1, z_offset, i__1;
    /* Local variables */
    integer inde;
    char vect[1];
    extern logical lsame_(char *, char *);
    integer iinfo;
    logical upper, wantz;
    extern /* Subroutine */
    int chbtrd_(char *, char *, integer *, integer *, complex *, integer *, real *, real *, complex *, integer *, complex *, integer *), chbgst_(char *, char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, complex *, real *, integer *), xerbla_(char *, integer *), cpbstf_(char *, integer *, integer *, complex *, integer *, integer *);
    integer indwrk;
    extern /* Subroutine */
    int csteqr_(char *, integer *, real *, real *, complex *, integer *, real *, integer *), ssterf_(integer *, real *, real *, integer *);
    /* -- LAPACK driver routine (version 3.4.0) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* November 2011 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Test the input parameters. */
    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    bb_dim1 = *ldbb;
    bb_offset = 1 + bb_dim1;
    bb -= bb_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --work;
    --rwork;
    /* Function Body */
    wantz = lsame_(jobz, "V");
    upper = lsame_(uplo, "U");
    *info = 0;
    if (! (wantz || lsame_(jobz, "N")))
    {
        *info = -1;
    }
    else if (! (upper || lsame_(uplo, "L")))
    {
        *info = -2;
    }
    else if (*n < 0)
    {
        *info = -3;
    }
    else if (*ka < 0)
    {
        *info = -4;
    }
    else if (*kb < 0 || *kb > *ka)
    {
        *info = -5;
    }
    else if (*ldab < *ka + 1)
    {
        *info = -7;
    }
    else if (*ldbb < *kb + 1)
    {
        *info = -9;
    }
    else if (*ldz < 1 || wantz && *ldz < *n)
    {
        *info = -12;
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CHBGV ", &i__1);
        return 0;
    }
    /* Quick return if possible */
    if (*n == 0)
    {
        return 0;
    }
    /* Form a split Cholesky factorization of B. */
    cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
    if (*info != 0)
    {
        *info = *n + *info;
        return 0;
    }
    /* Transform problem to standard eigenvalue problem. */
    inde = 1;
    indwrk = inde + *n;
    chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb, &z__[z_offset], ldz, &work[1], &rwork[indwrk], &iinfo);
    /* Reduce to tridiagonal form. */
    if (wantz)
    {
        *(unsigned char *)vect = 'U';
    }
    else
    {
        *(unsigned char *)vect = 'N';
    }
    chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &w[1], &rwork[inde], & z__[z_offset], ldz, &work[1], &iinfo);
    /* For eigenvalues only, call SSTERF. For eigenvectors, call CSTEQR. */
    if (! wantz)
    {
        ssterf_(n, &w[1], &rwork[inde], info);
    }
    else
    {
        csteqr_(jobz, n, &w[1], &rwork[inde], &z__[z_offset], ldz, &rwork[ indwrk], info);
    }
    return 0;
    /* End of CHBGV */
}
Esempio n. 4
0
/* Subroutine */ int chbevx_(char *jobz, char *range, char *uplo, integer *n, 
	integer *kd, complex *ab, integer *ldab, complex *q, integer *ldq, 
	real *vl, real *vu, integer *il, integer *iu, real *abstol, integer *
	m, real *w, complex *z__, integer *ldz, complex *work, real *rwork, 
	integer *iwork, integer *ifail, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, q_dim1, q_offset, z_dim1, z_offset, i__1, 
	    i__2;
    real r__1, r__2;

    /* Local variables */
    integer i__, j, jj;
    real eps, vll, vuu, tmp1;
    integer indd, inde;
    real anrm;
    integer imax;
    real rmin, rmax;
    logical test;
    complex ctmp1;
    integer itmp1, indee;
    real sigma;
    integer iinfo;
    char order[1];
    logical lower;
    logical wantz;
    logical alleig, indeig;
    integer iscale, indibl;
    logical valeig;
    real safmin;
    real abstll, bignum;
    integer indiwk, indisp;
    integer indrwk, indwrk;
    integer nsplit;
    real smlnum;

/*  -- LAPACK driver routine (version 3.2) -- */
/*     November 2006 */

/*  Purpose */
/*  ======= */

/*  CHBEVX computes selected eigenvalues and, optionally, eigenvectors */
/*  of a complex Hermitian band matrix A.  Eigenvalues and eigenvectors */
/*  can be selected by specifying either a range of values or a range of */
/*  indices for the desired eigenvalues. */

/*  Arguments */
/*  ========= */

/*  JOBZ    (input) CHARACTER*1 */
/*          = 'N':  Compute eigenvalues only; */
/*          = 'V':  Compute eigenvalues and eigenvectors. */

/*  RANGE   (input) CHARACTER*1 */
/*          = 'A': all eigenvalues will be found; */
/*          = 'V': all eigenvalues in the half-open interval (VL,VU] */
/*                 will be found; */
/*          = 'I': the IL-th through IU-th eigenvalues will be found. */

/*  UPLO    (input) CHARACTER*1 */
/*          = 'U':  Upper triangle of A is stored; */
/*          = 'L':  Lower triangle of A is stored. */

/*  N       (input) INTEGER */
/*          The order of the matrix A.  N >= 0. */

/*  KD      (input) INTEGER */
/*          The number of superdiagonals of the matrix A if UPLO = 'U', */
/*          or the number of subdiagonals if UPLO = 'L'.  KD >= 0. */

/*  AB      (input/output) COMPLEX array, dimension (LDAB, N) */
/*          On entry, the upper or lower triangle of the Hermitian band */
/*          matrix A, stored in the first KD+1 rows of the array.  The */
/*          j-th column of A is stored in the j-th column of the array AB */
/*          as follows: */
/*          if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; */
/*          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd). */

/*          On exit, AB is overwritten by values generated during the */
/*          reduction to tridiagonal form. */

/*  LDAB    (input) INTEGER */
/*          The leading dimension of the array AB.  LDAB >= KD + 1. */

/*  Q       (output) COMPLEX array, dimension (LDQ, N) */
/*          If JOBZ = 'V', the N-by-N unitary matrix used in the */
/*                          reduction to tridiagonal form. */
/*          If JOBZ = 'N', the array Q is not referenced. */

/*  LDQ     (input) INTEGER */
/*          The leading dimension of the array Q.  If JOBZ = 'V', then */
/*          LDQ >= max(1,N). */

/*  VL      (input) REAL */
/*  VU      (input) REAL */
/*          If RANGE='V', the lower and upper bounds of the interval to */
/*          be searched for eigenvalues. VL < VU. */
/*          Not referenced if RANGE = 'A' or 'I'. */

/*  IL      (input) INTEGER */
/*  IU      (input) INTEGER */
/*          If RANGE='I', the indices (in ascending order) of the */
/*          smallest and largest eigenvalues to be returned. */
/*          1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. */
/*          Not referenced if RANGE = 'A' or 'V'. */

/*  ABSTOL  (input) REAL */
/*          The absolute error tolerance for the eigenvalues. */
/*          An approximate eigenvalue is accepted as converged */
/*          when it is determined to lie in an interval [a,b] */
/*          of width less than or equal to */

/*                  ABSTOL + EPS *   max( |a|,|b| ) , */

/*          where EPS is the machine precision.  If ABSTOL is less than */
/*          or equal to zero, then  EPS*|T|  will be used in its place, */
/*          where |T| is the 1-norm of the tridiagonal matrix obtained */
/*          by reducing AB to tridiagonal form. */

/*          Eigenvalues will be computed most accurately when ABSTOL is */
/*          set to twice the underflow threshold 2*SLAMCH('S'), not zero. */
/*          If this routine returns with INFO>0, indicating that some */
/*          eigenvectors did not converge, try setting ABSTOL to */
/*          2*SLAMCH('S'). */

/*          See "Computing Small Singular Values of Bidiagonal Matrices */
/*          with Guaranteed High Relative Accuracy," by Demmel and */
/*          Kahan, LAPACK Working Note #3. */

/*  M       (output) INTEGER */
/*          The total number of eigenvalues found.  0 <= M <= N. */
/*          If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1. */

/*  W       (output) REAL array, dimension (N) */
/*          The first M elements contain the selected eigenvalues in */
/*          ascending order. */

/*  Z       (output) COMPLEX array, dimension (LDZ, max(1,M)) */
/*          If JOBZ = 'V', then if INFO = 0, the first M columns of Z */
/*          contain the orthonormal eigenvectors of the matrix A */
/*          corresponding to the selected eigenvalues, with the i-th */
/*          column of Z holding the eigenvector associated with W(i). */
/*          If an eigenvector fails to converge, then that column of Z */
/*          contains the latest approximation to the eigenvector, and the */
/*          index of the eigenvector is returned in IFAIL. */
/*          If JOBZ = 'N', then Z is not referenced. */
/*          Note: the user must ensure that at least max(1,M) columns are */
/*          supplied in the array Z; if RANGE = 'V', the exact value of M */
/*          is not known in advance and an upper bound must be used. */

/*  LDZ     (input) INTEGER */
/*          The leading dimension of the array Z.  LDZ >= 1, and if */
/*          JOBZ = 'V', LDZ >= max(1,N). */

/*  WORK    (workspace) COMPLEX array, dimension (N) */

/*  RWORK   (workspace) REAL array, dimension (7*N) */

/*  IWORK   (workspace) INTEGER array, dimension (5*N) */

/*  IFAIL   (output) INTEGER array, dimension (N) */
/*          If JOBZ = 'V', then if INFO = 0, the first M elements of */
/*          IFAIL are zero.  If INFO > 0, then IFAIL contains the */
/*          indices of the eigenvectors that failed to converge. */
/*          If JOBZ = 'N', then IFAIL is not referenced. */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value */
/*          > 0:  if INFO = i, then i eigenvectors failed to converge. */
/*                Their indices are stored in array IFAIL. */

/*  ===================================================================== */

/*     Test the input parameters. */

    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    q_dim1 = *ldq;
    q_offset = 1 + q_dim1;
    q -= q_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --work;
    --rwork;
    --iwork;
    --ifail;

    /* Function Body */
    wantz = lsame_(jobz, "V");
    alleig = lsame_(range, "A");
    valeig = lsame_(range, "V");
    indeig = lsame_(range, "I");
    lower = lsame_(uplo, "L");

    *info = 0;
    if (! (wantz || lsame_(jobz, "N"))) {
	*info = -1;
    } else if (! (alleig || valeig || indeig)) {
	*info = -2;
    } else if (! (lower || lsame_(uplo, "U"))) {
	*info = -3;
    } else if (*n < 0) {
	*info = -4;
    } else if (*kd < 0) {
	*info = -5;
    } else if (*ldab < *kd + 1) {
	*info = -7;
    } else if (wantz && *ldq < max(1,*n)) {
	*info = -9;
    } else {
	if (valeig) {
	    if (*n > 0 && *vu <= *vl) {
		*info = -11;
	    }
	} else if (indeig) {
	    if (*il < 1 || *il > max(1,*n)) {
		*info = -12;
	    } else if (*iu < min(*n,*il) || *iu > *n) {
		*info = -13;
	    }
	}
    }
    if (*info == 0) {
	if (*ldz < 1 || wantz && *ldz < *n) {
	    *info = -18;
	}
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHBEVX", &i__1);
	return 0;
    }

/*     Quick return if possible */

    *m = 0;
    if (*n == 0) {
	return 0;
    }

    if (*n == 1) {
	*m = 1;
	if (lower) {
	    i__1 = ab_dim1 + 1;
	    ctmp1.r = ab[i__1].r, ctmp1.i = ab[i__1].i;
	} else {
	    i__1 = *kd + 1 + ab_dim1;
	    ctmp1.r = ab[i__1].r, ctmp1.i = ab[i__1].i;
	}
	tmp1 = ctmp1.r;
	if (valeig) {
	    if (! (*vl < tmp1 && *vu >= tmp1)) {
		*m = 0;
	    }
	}
	if (*m == 1) {
	    w[1] = ctmp1.r;
	    if (wantz) {
		i__1 = z_dim1 + 1;
		z__[i__1].r = 1.f, z__[i__1].i = 0.f;
	    }
	}
	return 0;
    }

/*     Get machine constants. */

    safmin = slamch_("Safe minimum");
    eps = slamch_("Precision");
    smlnum = safmin / eps;
    bignum = 1.f / smlnum;
    rmin = sqrt(smlnum);
/* Computing MIN */
    r__1 = sqrt(bignum), r__2 = 1.f / sqrt(sqrt(safmin));
    rmax = dmin(r__1,r__2);

/*     Scale matrix to allowable range, if necessary. */

    iscale = 0;
    abstll = *abstol;
    if (valeig) {
	vll = *vl;
	vuu = *vu;
    } else {
	vll = 0.f;
	vuu = 0.f;
    }
    anrm = clanhb_("M", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]);
    if (anrm > 0.f && anrm < rmin) {
	iscale = 1;
	sigma = rmin / anrm;
    } else if (anrm > rmax) {
	iscale = 1;
	sigma = rmax / anrm;
    }
    if (iscale == 1) {
	if (lower) {
	    clascl_("B", kd, kd, &c_b16, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	} else {
	    clascl_("Q", kd, kd, &c_b16, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	}
	if (*abstol > 0.f) {
	    abstll = *abstol * sigma;
	}
	if (valeig) {
	    vll = *vl * sigma;
	    vuu = *vu * sigma;
	}
    }

/*     Call CHBTRD to reduce Hermitian band matrix to tridiagonal form. */

    indd = 1;
    inde = indd + *n;
    indrwk = inde + *n;
    indwrk = 1;
    chbtrd_(jobz, uplo, n, kd, &ab[ab_offset], ldab, &rwork[indd], &rwork[
	    inde], &q[q_offset], ldq, &work[indwrk], &iinfo);

/*     If all eigenvalues are desired and ABSTOL is less than or equal */
/*     to zero, then call SSTERF or CSTEQR.  If this fails for some */
/*     eigenvalue, then try SSTEBZ. */

    test = FALSE_;
    if (indeig) {
	if (*il == 1 && *iu == *n) {
	    test = TRUE_;
	}
    }
    if ((alleig || test) && *abstol <= 0.f) {
	scopy_(n, &rwork[indd], &c__1, &w[1], &c__1);
	indee = indrwk + (*n << 1);
	if (! wantz) {
	    i__1 = *n - 1;
	    scopy_(&i__1, &rwork[inde], &c__1, &rwork[indee], &c__1);
	    ssterf_(n, &w[1], &rwork[indee], info);
	} else {
	    clacpy_("A", n, n, &q[q_offset], ldq, &z__[z_offset], ldz);
	    i__1 = *n - 1;
	    scopy_(&i__1, &rwork[inde], &c__1, &rwork[indee], &c__1);
	    csteqr_(jobz, n, &w[1], &rwork[indee], &z__[z_offset], ldz, &
		    rwork[indrwk], info);
	    if (*info == 0) {
		i__1 = *n;
		for (i__ = 1; i__ <= i__1; ++i__) {
		    ifail[i__] = 0;
		}
	    }
	}
	if (*info == 0) {
	    *m = *n;
	    goto L30;
	}
	*info = 0;
    }

/*     Otherwise, call SSTEBZ and, if eigenvectors are desired, CSTEIN. */

    if (wantz) {
	*(unsigned char *)order = 'B';
    } else {
	*(unsigned char *)order = 'E';
    }
    indibl = 1;
    indisp = indibl + *n;
    indiwk = indisp + *n;
    sstebz_(range, order, n, &vll, &vuu, il, iu, &abstll, &rwork[indd], &
	    rwork[inde], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &
	    rwork[indrwk], &iwork[indiwk], info);

    if (wantz) {
	cstein_(n, &rwork[indd], &rwork[inde], m, &w[1], &iwork[indibl], &
		iwork[indisp], &z__[z_offset], ldz, &rwork[indrwk], &iwork[
		indiwk], &ifail[1], info);

/*        Apply unitary matrix used in reduction to tridiagonal */
/*        form to eigenvectors returned by CSTEIN. */

	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    ccopy_(n, &z__[j * z_dim1 + 1], &c__1, &work[1], &c__1);
	    cgemv_("N", n, n, &c_b2, &q[q_offset], ldq, &work[1], &c__1, &
		    c_b1, &z__[j * z_dim1 + 1], &c__1);
	}
    }

/*     If matrix was scaled, then rescale eigenvalues appropriately. */

L30:
    if (iscale == 1) {
	if (*info == 0) {
	    imax = *m;
	} else {
	    imax = *info - 1;
	}
	r__1 = 1.f / sigma;
	sscal_(&imax, &r__1, &w[1], &c__1);
    }

/*     If eigenvalues are not in order, then sort them, along with */
/*     eigenvectors. */

    if (wantz) {
	i__1 = *m - 1;
	for (j = 1; j <= i__1; ++j) {
	    i__ = 0;
	    tmp1 = w[j];
	    i__2 = *m;
	    for (jj = j + 1; jj <= i__2; ++jj) {
		if (w[jj] < tmp1) {
		    i__ = jj;
		    tmp1 = w[jj];
		}
	    }

	    if (i__ != 0) {
		itmp1 = iwork[indibl + i__ - 1];
		w[i__] = w[j];
		iwork[indibl + i__ - 1] = iwork[indibl + j - 1];
		w[j] = tmp1;
		iwork[indibl + j - 1] = itmp1;
		cswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[j * z_dim1 + 1], 
			 &c__1);
		if (*info != 0) {
		    itmp1 = ifail[i__];
		    ifail[i__] = ifail[j];
		    ifail[j] = itmp1;
		}
	    }
	}
    }

    return 0;

/*     End of CHBEVX */

} /* chbevx_ */
Esempio n. 5
0
/* Subroutine */ int chbgvd_(char *jobz, char *uplo, integer *n, integer *ka, 
	integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb, 
	real *w, complex *z__, integer *ldz, complex *work, integer *lwork, 
	real *rwork, integer *lrwork, integer *iwork, integer *liwork, 
	integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, bb_dim1, bb_offset, z_dim1, z_offset, i__1;

    /* Local variables */
    integer inde;
    char vect[1];
    integer llwk2;
    integer iinfo, lwmin;
    logical upper;
    integer llrwk;
    logical wantz;
    integer indwk2;
    integer indwrk, liwmin;
    integer lrwmin;
    logical lquery;

/*  -- LAPACK driver routine (version 3.2) -- */
/*     November 2006 */

/*  Purpose */
/*  ======= */

/*  CHBGVD computes all the eigenvalues, and optionally, the eigenvectors */
/*  of a complex generalized Hermitian-definite banded eigenproblem, of */
/*  the form A*x=(lambda)*B*x. Here A and B are assumed to be Hermitian */
/*  and banded, and B is also positive definite.  If eigenvectors are */
/*  desired, it uses a divide and conquer algorithm. */

/*  The divide and conquer algorithm makes very mild assumptions about */
/*  floating point arithmetic. It will work on machines with a guard */
/*  digit in add/subtract, or on those binary machines without guard */
/*  digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or */
/*  Cray-2. It could conceivably fail on hexadecimal or decimal machines */
/*  without guard digits, but we know of none. */

/*  Arguments */
/*  ========= */

/*  JOBZ    (input) CHARACTER*1 */
/*          = 'N':  Compute eigenvalues only; */
/*          = 'V':  Compute eigenvalues and eigenvectors. */

/*  UPLO    (input) CHARACTER*1 */
/*          = 'U':  Upper triangles of A and B are stored; */
/*          = 'L':  Lower triangles of A and B are stored. */

/*  N       (input) INTEGER */
/*          The order of the matrices A and B.  N >= 0. */

/*  KA      (input) INTEGER */
/*          The number of superdiagonals of the matrix A if UPLO = 'U', */
/*          or the number of subdiagonals if UPLO = 'L'. KA >= 0. */

/*  KB      (input) INTEGER */
/*          The number of superdiagonals of the matrix B if UPLO = 'U', */
/*          or the number of subdiagonals if UPLO = 'L'. KB >= 0. */

/*  AB      (input/output) COMPLEX array, dimension (LDAB, N) */
/*          On entry, the upper or lower triangle of the Hermitian band */
/*          matrix A, stored in the first ka+1 rows of the array.  The */
/*          j-th column of A is stored in the j-th column of the array AB */
/*          as follows: */
/*          if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-ka)<=i<=j; */
/*          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+ka). */

/*          On exit, the contents of AB are destroyed. */

/*  LDAB    (input) INTEGER */
/*          The leading dimension of the array AB.  LDAB >= KA+1. */

/*  BB      (input/output) COMPLEX array, dimension (LDBB, N) */
/*          On entry, the upper or lower triangle of the Hermitian band */
/*          matrix B, stored in the first kb+1 rows of the array.  The */
/*          j-th column of B is stored in the j-th column of the array BB */
/*          as follows: */
/*          if UPLO = 'U', BB(kb+1+i-j,j) = B(i,j) for max(1,j-kb)<=i<=j; */
/*          if UPLO = 'L', BB(1+i-j,j)    = B(i,j) for j<=i<=min(n,j+kb). */

/*          On exit, the factor S from the split Cholesky factorization */
/*          B = S**H*S, as returned by CPBSTF. */

/*  LDBB    (input) INTEGER */
/*          The leading dimension of the array BB.  LDBB >= KB+1. */

/*  W       (output) REAL array, dimension (N) */
/*          If INFO = 0, the eigenvalues in ascending order. */

/*  Z       (output) COMPLEX array, dimension (LDZ, N) */
/*          If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of */
/*          eigenvectors, with the i-th column of Z holding the */
/*          eigenvector associated with W(i). The eigenvectors are */
/*          normalized so that Z**H*B*Z = I. */
/*          If JOBZ = 'N', then Z is not referenced. */

/*  LDZ     (input) INTEGER */
/*          The leading dimension of the array Z.  LDZ >= 1, and if */
/*          JOBZ = 'V', LDZ >= N. */

/*  WORK    (workspace/output) COMPLEX array, dimension (MAX(1,LWORK)) */
/*          On exit, if INFO=0, WORK(1) returns the optimal LWORK. */

/*  LWORK   (input) INTEGER */
/*          The dimension of the array WORK. */
/*          If N <= 1,               LWORK >= 1. */
/*          If JOBZ = 'N' and N > 1, LWORK >= N. */
/*          If JOBZ = 'V' and N > 1, LWORK >= 2*N**2. */

/*          If LWORK = -1, then a workspace query is assumed; the routine */
/*          only calculates the optimal sizes of the WORK, RWORK and */
/*          IWORK arrays, returns these values as the first entries of */
/*          the WORK, RWORK and IWORK arrays, and no error message */
/*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */

/*  RWORK   (workspace/output) REAL array, dimension (MAX(1,LRWORK)) */
/*          On exit, if INFO=0, RWORK(1) returns the optimal LRWORK. */

/*  LRWORK  (input) INTEGER */
/*          The dimension of array RWORK. */
/*          If N <= 1,               LRWORK >= 1. */
/*          If JOBZ = 'N' and N > 1, LRWORK >= N. */
/*          If JOBZ = 'V' and N > 1, LRWORK >= 1 + 5*N + 2*N**2. */

/*          If LRWORK = -1, then a workspace query is assumed; the */
/*          routine only calculates the optimal sizes of the WORK, RWORK */
/*          and IWORK arrays, returns these values as the first entries */
/*          of the WORK, RWORK and IWORK arrays, and no error message */
/*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */

/*  IWORK   (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) */
/*          On exit, if INFO=0, IWORK(1) returns the optimal LIWORK. */

/*  LIWORK  (input) INTEGER */
/*          The dimension of array IWORK. */
/*          If JOBZ = 'N' or N <= 1, LIWORK >= 1. */
/*          If JOBZ = 'V' and N > 1, LIWORK >= 3 + 5*N. */

/*          If LIWORK = -1, then a workspace query is assumed; the */
/*          routine only calculates the optimal sizes of the WORK, RWORK */
/*          and IWORK arrays, returns these values as the first entries */
/*          of the WORK, RWORK and IWORK arrays, and no error message */
/*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value */
/*          > 0:  if INFO = i, and i is: */
/*             <= N:  the algorithm failed to converge: */
/*                    i off-diagonal elements of an intermediate */
/*                    tridiagonal form did not converge to zero; */
/*             > N:   if INFO = N + i, for 1 <= i <= N, then CPBSTF */
/*                    returned INFO = i: B is not positive definite. */
/*                    The factorization of B could not be completed and */
/*                    no eigenvalues or eigenvectors were computed. */

/*  Further Details */
/*  =============== */

/*  Based on contributions by */
/*     Mark Fahey, Department of Mathematics, Univ. of Kentucky, USA */

/*  ===================================================================== */

/*     Test the input parameters. */

    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    bb_dim1 = *ldbb;
    bb_offset = 1 + bb_dim1;
    bb -= bb_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --work;
    --rwork;
    --iwork;

    /* Function Body */
    wantz = lsame_(jobz, "V");
    upper = lsame_(uplo, "U");
    lquery = *lwork == -1 || *lrwork == -1 || *liwork == -1;

    *info = 0;
    if (*n <= 1) {
	lwmin = 1;
	lrwmin = 1;
	liwmin = 1;
    } else if (wantz) {
/* Computing 2nd power */
	i__1 = *n;
	lwmin = i__1 * i__1 << 1;
/* Computing 2nd power */
	i__1 = *n;
	lrwmin = *n * 5 + 1 + (i__1 * i__1 << 1);
	liwmin = *n * 5 + 3;
    } else {
	lwmin = *n;
	lrwmin = *n;
	liwmin = 1;
    }
    if (! (wantz || lsame_(jobz, "N"))) {
	*info = -1;
    } else if (! (upper || lsame_(uplo, "L"))) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (*ka < 0) {
	*info = -4;
    } else if (*kb < 0 || *kb > *ka) {
	*info = -5;
    } else if (*ldab < *ka + 1) {
	*info = -7;
    } else if (*ldbb < *kb + 1) {
	*info = -9;
    } else if (*ldz < 1 || wantz && *ldz < *n) {
	*info = -12;
    }

    if (*info == 0) {
	work[1].r = (real) lwmin, work[1].i = 0.f;
	rwork[1] = (real) lrwmin;
	iwork[1] = liwmin;

	if (*lwork < lwmin && ! lquery) {
	    *info = -14;
	} else if (*lrwork < lrwmin && ! lquery) {
	    *info = -16;
	} else if (*liwork < liwmin && ! lquery) {
	    *info = -18;
	}
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHBGVD", &i__1);
	return 0;
    } else if (lquery) {
	return 0;
    }

/*     Quick return if possible */

    if (*n == 0) {
	return 0;
    }

/*     Form a split Cholesky factorization of B. */

    cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
    if (*info != 0) {
	*info = *n + *info;
	return 0;
    }

/*     Transform problem to standard eigenvalue problem. */

    inde = 1;
    indwrk = inde + *n;
    indwk2 = *n * *n + 1;
    llwk2 = *lwork - indwk2 + 2;
    llrwk = *lrwork - indwrk + 2;
    chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb, 
	     &z__[z_offset], ldz, &work[1], &rwork[indwrk], &iinfo);

/*     Reduce Hermitian band matrix to tridiagonal form. */

    if (wantz) {
	*(unsigned char *)vect = 'U';
    } else {
	*(unsigned char *)vect = 'N';
    }
    chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &w[1], &rwork[inde], &
	    z__[z_offset], ldz, &work[1], &iinfo);

/*     For eigenvalues only, call SSTERF.  For eigenvectors, call CSTEDC. */

    if (! wantz) {
	ssterf_(n, &w[1], &rwork[inde], info);
    } else {
	cstedc_("I", n, &w[1], &rwork[inde], &work[1], n, &work[indwk2], &
		llwk2, &rwork[indwrk], &llrwk, &iwork[1], liwork, info);
	cgemm_("N", "N", n, n, n, &c_b1, &z__[z_offset], ldz, &work[1], n, &
		c_b2, &work[indwk2], n);
	clacpy_("A", n, n, &work[indwk2], n, &z__[z_offset], ldz);
    }

    work[1].r = (real) lwmin, work[1].i = 0.f;
    rwork[1] = (real) lrwmin;
    iwork[1] = liwmin;
    return 0;

/*     End of CHBGVD */

} /* chbgvd_ */
Esempio n. 6
0
/* Subroutine */
int chbgvx_(char *jobz, char *range, char *uplo, integer *n, integer *ka, integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb, complex *q, integer *ldq, real *vl, real *vu, integer * il, integer *iu, real *abstol, integer *m, real *w, complex *z__, integer *ldz, complex *work, real *rwork, integer *iwork, integer * ifail, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, bb_dim1, bb_offset, q_dim1, q_offset, z_dim1, z_offset, i__1, i__2;
    /* Local variables */
    integer i__, j, jj;
    real tmp1;
    integer indd, inde;
    char vect[1];
    logical test;
    integer itmp1, indee;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */
    int cgemv_(char *, integer *, integer *, complex * , complex *, integer *, complex *, integer *, complex *, complex * , integer *);
    integer iinfo;
    char order[1];
    extern /* Subroutine */
    int ccopy_(integer *, complex *, integer *, complex *, integer *), cswap_(integer *, complex *, integer *, complex *, integer *);
    logical upper;
    extern /* Subroutine */
    int scopy_(integer *, real *, integer *, real *, integer *);
    logical wantz, alleig, indeig;
    integer indibl;
    extern /* Subroutine */
    int chbtrd_(char *, char *, integer *, integer *, complex *, integer *, real *, real *, complex *, integer *, complex *, integer *);
    logical valeig;
    extern /* Subroutine */
    int chbgst_(char *, char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, complex *, real *, integer *), clacpy_( char *, integer *, integer *, complex *, integer *, complex *, integer *), xerbla_(char *, integer *), cpbstf_( char *, integer *, integer *, complex *, integer *, integer *);
    integer indiwk, indisp;
    extern /* Subroutine */
    int cstein_(integer *, real *, real *, integer *, real *, integer *, integer *, complex *, integer *, real *, integer *, integer *, integer *);
    integer indrwk, indwrk;
    extern /* Subroutine */
    int csteqr_(char *, integer *, real *, real *, complex *, integer *, real *, integer *), ssterf_(integer *, real *, real *, integer *);
    integer nsplit;
    extern /* Subroutine */
    int sstebz_(char *, char *, integer *, real *, real *, integer *, integer *, real *, real *, real *, integer *, integer *, real *, integer *, integer *, real *, integer *, integer *);
    /* -- LAPACK driver routine (version 3.4.0) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* November 2011 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Parameters .. */
    /* .. */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Test the input parameters. */
    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    bb_dim1 = *ldbb;
    bb_offset = 1 + bb_dim1;
    bb -= bb_offset;
    q_dim1 = *ldq;
    q_offset = 1 + q_dim1;
    q -= q_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --work;
    --rwork;
    --iwork;
    --ifail;
    /* Function Body */
    wantz = lsame_(jobz, "V");
    upper = lsame_(uplo, "U");
    alleig = lsame_(range, "A");
    valeig = lsame_(range, "V");
    indeig = lsame_(range, "I");
    *info = 0;
    if (! (wantz || lsame_(jobz, "N")))
    {
        *info = -1;
    }
    else if (! (alleig || valeig || indeig))
    {
        *info = -2;
    }
    else if (! (upper || lsame_(uplo, "L")))
    {
        *info = -3;
    }
    else if (*n < 0)
    {
        *info = -4;
    }
    else if (*ka < 0)
    {
        *info = -5;
    }
    else if (*kb < 0 || *kb > *ka)
    {
        *info = -6;
    }
    else if (*ldab < *ka + 1)
    {
        *info = -8;
    }
    else if (*ldbb < *kb + 1)
    {
        *info = -10;
    }
    else if (*ldq < 1 || wantz && *ldq < *n)
    {
        *info = -12;
    }
    else
    {
        if (valeig)
        {
            if (*n > 0 && *vu <= *vl)
            {
                *info = -14;
            }
        }
        else if (indeig)
        {
            if (*il < 1 || *il > max(1,*n))
            {
                *info = -15;
            }
            else if (*iu < min(*n,*il) || *iu > *n)
            {
                *info = -16;
            }
        }
    }
    if (*info == 0)
    {
        if (*ldz < 1 || wantz && *ldz < *n)
        {
            *info = -21;
        }
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CHBGVX", &i__1);
        return 0;
    }
    /* Quick return if possible */
    *m = 0;
    if (*n == 0)
    {
        return 0;
    }
    /* Form a split Cholesky factorization of B. */
    cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
    if (*info != 0)
    {
        *info = *n + *info;
        return 0;
    }
    /* Transform problem to standard eigenvalue problem. */
    chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb, &q[q_offset], ldq, &work[1], &rwork[1], &iinfo);
    /* Solve the standard eigenvalue problem. */
    /* Reduce Hermitian band matrix to tridiagonal form. */
    indd = 1;
    inde = indd + *n;
    indrwk = inde + *n;
    indwrk = 1;
    if (wantz)
    {
        *(unsigned char *)vect = 'U';
    }
    else
    {
        *(unsigned char *)vect = 'N';
    }
    chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &rwork[indd], &rwork[ inde], &q[q_offset], ldq, &work[indwrk], &iinfo);
    /* If all eigenvalues are desired and ABSTOL is less than or equal */
    /* to zero, then call SSTERF or CSTEQR. If this fails for some */
    /* eigenvalue, then try SSTEBZ. */
    test = FALSE_;
    if (indeig)
    {
        if (*il == 1 && *iu == *n)
        {
            test = TRUE_;
        }
    }
    if ((alleig || test) && *abstol <= 0.f)
    {
        scopy_(n, &rwork[indd], &c__1, &w[1], &c__1);
        indee = indrwk + (*n << 1);
        i__1 = *n - 1;
        scopy_(&i__1, &rwork[inde], &c__1, &rwork[indee], &c__1);
        if (! wantz)
        {
            ssterf_(n, &w[1], &rwork[indee], info);
        }
        else
        {
            clacpy_("A", n, n, &q[q_offset], ldq, &z__[z_offset], ldz);
            csteqr_(jobz, n, &w[1], &rwork[indee], &z__[z_offset], ldz, & rwork[indrwk], info);
            if (*info == 0)
            {
                i__1 = *n;
                for (i__ = 1;
                        i__ <= i__1;
                        ++i__)
                {
                    ifail[i__] = 0;
                    /* L10: */
                }
            }
        }
        if (*info == 0)
        {
            *m = *n;
            goto L30;
        }
        *info = 0;
    }
    /* Otherwise, call SSTEBZ and, if eigenvectors are desired, */
    /* call CSTEIN. */
    if (wantz)
    {
        *(unsigned char *)order = 'B';
    }
    else
    {
        *(unsigned char *)order = 'E';
    }
    indibl = 1;
    indisp = indibl + *n;
    indiwk = indisp + *n;
    sstebz_(range, order, n, vl, vu, il, iu, abstol, &rwork[indd], &rwork[ inde], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &rwork[ indrwk], &iwork[indiwk], info);
    if (wantz)
    {
        cstein_(n, &rwork[indd], &rwork[inde], m, &w[1], &iwork[indibl], & iwork[indisp], &z__[z_offset], ldz, &rwork[indrwk], &iwork[ indiwk], &ifail[1], info);
        /* Apply unitary matrix used in reduction to tridiagonal */
        /* form to eigenvectors returned by CSTEIN. */
        i__1 = *m;
        for (j = 1;
                j <= i__1;
                ++j)
        {
            ccopy_(n, &z__[j * z_dim1 + 1], &c__1, &work[1], &c__1);
            cgemv_("N", n, n, &c_b2, &q[q_offset], ldq, &work[1], &c__1, & c_b1, &z__[j * z_dim1 + 1], &c__1);
            /* L20: */
        }
    }
L30: /* If eigenvalues are not in order, then sort them, along with */
    /* eigenvectors. */
    if (wantz)
    {
        i__1 = *m - 1;
        for (j = 1;
                j <= i__1;
                ++j)
        {
            i__ = 0;
            tmp1 = w[j];
            i__2 = *m;
            for (jj = j + 1;
                    jj <= i__2;
                    ++jj)
            {
                if (w[jj] < tmp1)
                {
                    i__ = jj;
                    tmp1 = w[jj];
                }
                /* L40: */
            }
            if (i__ != 0)
            {
                itmp1 = iwork[indibl + i__ - 1];
                w[i__] = w[j];
                iwork[indibl + i__ - 1] = iwork[indibl + j - 1];
                w[j] = tmp1;
                iwork[indibl + j - 1] = itmp1;
                cswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[j * z_dim1 + 1], &c__1);
                if (*info != 0)
                {
                    itmp1 = ifail[i__];
                    ifail[i__] = ifail[j];
                    ifail[j] = itmp1;
                }
            }
            /* L50: */
        }
    }
    return 0;
    /* End of CHBGVX */
}
Esempio n. 7
0
/* Subroutine */ int cchkhb_(integer *nsizes, integer *nn, integer *nwdths, 
	integer *kk, integer *ntypes, logical *dotype, integer *iseed, real *
	thresh, integer *nounit, complex *a, integer *lda, real *sd, real *se, 
	 complex *u, integer *ldu, complex *work, integer *lwork, real *rwork, 
	 real *result, integer *info)
{
    /* Initialized data */

    static integer ktype[15] = { 1,2,4,4,4,4,4,5,5,5,5,5,8,8,8 };
    static integer kmagn[15] = { 1,1,1,1,1,2,3,1,1,1,2,3,1,2,3 };
    static integer kmode[15] = { 0,0,4,3,1,4,4,4,3,1,4,4,0,0,0 };

    /* Format strings */
    static char fmt_9999[] = "(\002 CCHKHB: \002,a,\002 returned INFO=\002,i"
	    "6,\002.\002,/9x,\002N=\002,i6,\002, JTYPE=\002,i6,\002, ISEED="
	    "(\002,3(i5,\002,\002),i5,\002)\002)";
    static char fmt_9998[] = "(/1x,a3,\002 -- Complex Hermitian Banded Tridi"
	    "agonal Reduction Routines\002)";
    static char fmt_9997[] = "(\002 Matrix types (see SCHK23 for details):"
	    " \002)";
    static char fmt_9996[] = "(/\002 Special Matrices:\002,/\002  1=Zero mat"
	    "rix.                        \002,\002  5=Diagonal: clustered ent"
	    "ries.\002,/\002  2=Identity matrix.                    \002,\002"
	    "  6=Diagonal: large, evenly spaced.\002,/\002  3=Diagonal: evenl"
	    "y spaced entries.    \002,\002  7=Diagonal: small, evenly spaced."
	    "\002,/\002  4=Diagonal: geometr. spaced entries.\002)";
    static char fmt_9995[] = "(\002 Dense \002,a,\002 Banded Matrices:\002,"
	    "/\002  8=Evenly spaced eigenvals.            \002,\002 12=Small,"
	    " evenly spaced eigenvals.\002,/\002  9=Geometrically spaced eige"
	    "nvals.     \002,\002 13=Matrix with random O(1) entries.\002,"
	    "/\002 10=Clustered eigenvalues.              \002,\002 14=Matrix"
	    " with large random entries.\002,/\002 11=Large, evenly spaced ei"
	    "genvals.     \002,\002 15=Matrix with small random entries.\002)";
    static char fmt_9994[] = "(/\002 Tests performed:   (S is Tridiag,  U "
	    "is \002,a,\002,\002,/20x,a,\002 means \002,a,\002.\002,/\002 UPL"
	    "O='U':\002,/\002  1= | A - U S U\002,a1,\002 | / ( |A| n ulp )  "
	    "   \002,\002  2= | I - U U\002,a1,\002 | / ( n ulp )\002,/\002 U"
	    "PLO='L':\002,/\002  3= | A - U S U\002,a1,\002 | / ( |A| n ulp )"
	    "     \002,\002  4= | I - U U\002,a1,\002 | / ( n ulp )\002)";
    static char fmt_9993[] = "(\002 N=\002,i5,\002, K=\002,i4,\002, seed="
	    "\002,4(i4,\002,\002),\002 type \002,i2,\002, test(\002,i2,\002)"
	    "=\002,g10.3)";

    /* System generated locals */
    integer a_dim1, a_offset, u_dim1, u_offset, i__1, i__2, i__3, i__4, i__5, 
	    i__6, i__7;
    real r__1;
    complex q__1;

    /* Local variables */
    integer i__, j, k, n, jc, jr;
    real ulp, cond;
    integer jcol, kmax, nmax;
    real unfl, ovfl, temp1;
    logical badnn;
    extern /* Subroutine */ int chbt21_(char *, integer *, integer *, integer 
	    *, complex *, integer *, real *, real *, complex *, integer *, 
	    complex *, real *, real *);
    integer imode, iinfo;
    real aninv, anorm;
    integer nmats, jsize, nerrs, itype, jtype, ntest;
    logical badnnb;
    extern /* Subroutine */ int chbtrd_(char *, char *, integer *, integer *, 
	    complex *, integer *, real *, real *, complex *, integer *, 
	    complex *, integer *);
    extern doublereal slamch_(char *);
    extern /* Subroutine */ int clacpy_(char *, integer *, integer *, complex 
	    *, integer *, complex *, integer *);
    integer idumma[1];
    extern /* Subroutine */ int claset_(char *, integer *, integer *, complex 
	    *, complex *, complex *, integer *);
    integer ioldsd[4];
    extern /* Subroutine */ int xerbla_(char *, integer *), clatmr_(
	    integer *, integer *, char *, integer *, char *, complex *, 
	    integer *, real *, complex *, char *, char *, complex *, integer *
, real *, complex *, integer *, real *, char *, integer *, 
	    integer *, integer *, real *, real *, char *, complex *, integer *
, integer *, integer *), clatms_(integer *, integer *, char *, integer *, char *, 
	    real *, integer *, real *, real *, integer *, integer *, char *, 
	    complex *, integer *, complex *, integer *);
    integer jwidth;
    extern /* Subroutine */ int slasum_(char *, integer *, integer *, integer 
	    *);
    real rtunfl, rtovfl, ulpinv;
    integer mtypes, ntestt;

    /* Fortran I/O blocks */
    static cilist io___36 = { 0, 0, 0, fmt_9999, 0 };
    static cilist io___37 = { 0, 0, 0, fmt_9999, 0 };
    static cilist io___40 = { 0, 0, 0, fmt_9999, 0 };
    static cilist io___41 = { 0, 0, 0, fmt_9998, 0 };
    static cilist io___42 = { 0, 0, 0, fmt_9997, 0 };
    static cilist io___43 = { 0, 0, 0, fmt_9996, 0 };
    static cilist io___44 = { 0, 0, 0, fmt_9995, 0 };
    static cilist io___45 = { 0, 0, 0, fmt_9994, 0 };
    static cilist io___46 = { 0, 0, 0, fmt_9993, 0 };



/*  -- LAPACK test routine (version 3.1) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  CCHKHB tests the reduction of a Hermitian band matrix to tridiagonal */
/*  from, used with the Hermitian eigenvalue problem. */

/*  CHBTRD factors a Hermitian band matrix A as  U S U* , where * means */
/*  conjugate transpose, S is symmetric tridiagonal, and U is unitary. */
/*  CHBTRD can use either just the lower or just the upper triangle */
/*  of A; CCHKHB checks both cases. */

/*  When CCHKHB is called, a number of matrix "sizes" ("n's"), a number */
/*  of bandwidths ("k's"), and a number of matrix "types" are */
/*  specified.  For each size ("n"), each bandwidth ("k") less than or */
/*  equal to "n", and each type of matrix, one matrix will be generated */
/*  and used to test the hermitian banded reduction routine.  For each */
/*  matrix, a number of tests will be performed: */

/*  (1)     | A - V S V* | / ( |A| n ulp )  computed by CHBTRD with */
/*                                          UPLO='U' */

/*  (2)     | I - UU* | / ( n ulp ) */

/*  (3)     | A - V S V* | / ( |A| n ulp )  computed by CHBTRD with */
/*                                          UPLO='L' */

/*  (4)     | I - UU* | / ( n ulp ) */

/*  The "sizes" are specified by an array NN(1:NSIZES); the value of */
/*  each element NN(j) specifies one size. */
/*  The "types" are specified by a logical array DOTYPE( 1:NTYPES ); */
/*  if DOTYPE(j) is .TRUE., then matrix type "j" will be generated. */
/*  Currently, the list of possible types is: */

/*  (1)  The zero matrix. */
/*  (2)  The identity matrix. */

/*  (3)  A diagonal matrix with evenly spaced entries */
/*       1, ..., ULP  and random signs. */
/*       (ULP = (first number larger than 1) - 1 ) */
/*  (4)  A diagonal matrix with geometrically spaced entries */
/*       1, ..., ULP  and random signs. */
/*  (5)  A diagonal matrix with "clustered" entries 1, ULP, ..., ULP */
/*       and random signs. */

/*  (6)  Same as (4), but multiplied by SQRT( overflow threshold ) */
/*  (7)  Same as (4), but multiplied by SQRT( underflow threshold ) */

/*  (8)  A matrix of the form  U* D U, where U is unitary and */
/*       D has evenly spaced entries 1, ..., ULP with random signs */
/*       on the diagonal. */

/*  (9)  A matrix of the form  U* D U, where U is unitary and */
/*       D has geometrically spaced entries 1, ..., ULP with random */
/*       signs on the diagonal. */

/*  (10) A matrix of the form  U* D U, where U is unitary and */
/*       D has "clustered" entries 1, ULP,..., ULP with random */
/*       signs on the diagonal. */

/*  (11) Same as (8), but multiplied by SQRT( overflow threshold ) */
/*  (12) Same as (8), but multiplied by SQRT( underflow threshold ) */

/*  (13) Hermitian matrix with random entries chosen from (-1,1). */
/*  (14) Same as (13), but multiplied by SQRT( overflow threshold ) */
/*  (15) Same as (13), but multiplied by SQRT( underflow threshold ) */

/*  Arguments */
/*  ========= */

/*  NSIZES  (input) INTEGER */
/*          The number of sizes of matrices to use.  If it is zero, */
/*          CCHKHB does nothing.  It must be at least zero. */

/*  NN      (input) INTEGER array, dimension (NSIZES) */
/*          An array containing the sizes to be used for the matrices. */
/*          Zero values will be skipped.  The values must be at least */
/*          zero. */

/*  NWDTHS  (input) INTEGER */
/*          The number of bandwidths to use.  If it is zero, */
/*          CCHKHB does nothing.  It must be at least zero. */

/*  KK      (input) INTEGER array, dimension (NWDTHS) */
/*          An array containing the bandwidths to be used for the band */
/*          matrices.  The values must be at least zero. */

/*  NTYPES  (input) INTEGER */
/*          The number of elements in DOTYPE.   If it is zero, CCHKHB */
/*          does nothing.  It must be at least zero.  If it is MAXTYP+1 */
/*          and NSIZES is 1, then an additional type, MAXTYP+1 is */
/*          defined, which is to use whatever matrix is in A.  This */
/*          is only useful if DOTYPE(1:MAXTYP) is .FALSE. and */
/*          DOTYPE(MAXTYP+1) is .TRUE. . */

/*  DOTYPE  (input) LOGICAL array, dimension (NTYPES) */
/*          If DOTYPE(j) is .TRUE., then for each size in NN a */
/*          matrix of that size and of type j will be generated. */
/*          If NTYPES is smaller than the maximum number of types */
/*          defined (PARAMETER MAXTYP), then types NTYPES+1 through */
/*          MAXTYP will not be generated.  If NTYPES is larger */
/*          than MAXTYP, DOTYPE(MAXTYP+1) through DOTYPE(NTYPES) */
/*          will be ignored. */

/*  ISEED   (input/output) INTEGER array, dimension (4) */
/*          On entry ISEED specifies the seed of the random number */
/*          generator. The array elements should be between 0 and 4095; */
/*          if not they will be reduced mod 4096.  Also, ISEED(4) must */
/*          be odd.  The random number generator uses a linear */
/*          congruential sequence limited to small integers, and so */
/*          should produce machine independent random numbers. The */
/*          values of ISEED are changed on exit, and can be used in the */
/*          next call to CCHKHB to continue the same random number */
/*          sequence. */

/*  THRESH  (input) REAL */
/*          A test will count as "failed" if the "error", computed as */
/*          described above, exceeds THRESH.  Note that the error */
/*          is scaled to be O(1), so THRESH should be a reasonably */
/*          small multiple of 1, e.g., 10 or 100.  In particular, */
/*          it should not depend on the precision (single vs. double) */
/*          or the size of the matrix.  It must be at least zero. */

/*  NOUNIT  (input) INTEGER */
/*          The FORTRAN unit number for printing out error messages */
/*          (e.g., if a routine returns IINFO not equal to 0.) */

/*  A       (input/workspace) REAL array, dimension */
/*                            (LDA, max(NN)) */
/*          Used to hold the matrix whose eigenvalues are to be */
/*          computed. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of A.  It must be at least 2 (not 1!) */
/*          and at least max( KK )+1. */

/*  SD      (workspace) REAL array, dimension (max(NN)) */
/*          Used to hold the diagonal of the tridiagonal matrix computed */
/*          by CHBTRD. */

/*  SE      (workspace) REAL array, dimension (max(NN)) */
/*          Used to hold the off-diagonal of the tridiagonal matrix */
/*          computed by CHBTRD. */

/*  U       (workspace) REAL array, dimension (LDU, max(NN)) */
/*          Used to hold the unitary matrix computed by CHBTRD. */

/*  LDU     (input) INTEGER */
/*          The leading dimension of U.  It must be at least 1 */
/*          and at least max( NN ). */

/*  WORK    (workspace) REAL array, dimension (LWORK) */

/*  LWORK   (input) INTEGER */
/*          The number of entries in WORK.  This must be at least */
/*          max( LDA+1, max(NN)+1 )*max(NN). */

/*  RESULT  (output) REAL array, dimension (4) */
/*          The values computed by the tests described above. */
/*          The values are currently limited to 1/ulp, to avoid */
/*          overflow. */

/*  INFO    (output) INTEGER */
/*          If 0, then everything ran OK. */

/* ----------------------------------------------------------------------- */

/*       Some Local Variables and Parameters: */
/*       ---- ----- --------- --- ---------- */
/*       ZERO, ONE       Real 0 and 1. */
/*       MAXTYP          The number of types defined. */
/*       NTEST           The number of tests performed, or which can */
/*                       be performed so far, for the current matrix. */
/*       NTESTT          The total number of tests performed so far. */
/*       NMAX            Largest value in NN. */
/*       NMATS           The number of matrices generated so far. */
/*       NERRS           The number of tests which have exceeded THRESH */
/*                       so far. */
/*       COND, IMODE     Values to be passed to the matrix generators. */
/*       ANORM           Norm of A; passed to matrix generators. */

/*       OVFL, UNFL      Overflow and underflow thresholds. */
/*       ULP, ULPINV     Finest relative precision and its inverse. */
/*       RTOVFL, RTUNFL  Square roots of the previous 2 values. */
/*               The following four arrays decode JTYPE: */
/*       KTYPE(j)        The general type (1-10) for type "j". */
/*       KMODE(j)        The MODE value to be passed to the matrix */
/*                       generator for type "j". */
/*       KMAGN(j)        The order of magnitude ( O(1), */
/*                       O(overflow^(1/2) ), O(underflow^(1/2) ) */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. Local Arrays .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Data statements .. */
    /* Parameter adjustments */
    --nn;
    --kk;
    --dotype;
    --iseed;
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --sd;
    --se;
    u_dim1 = *ldu;
    u_offset = 1 + u_dim1;
    u -= u_offset;
    --work;
    --rwork;
    --result;

    /* Function Body */
/*     .. */
/*     .. Executable Statements .. */

/*     Check for errors */

    ntestt = 0;
    *info = 0;

/*     Important constants */

    badnn = FALSE_;
    nmax = 1;
    i__1 = *nsizes;
    for (j = 1; j <= i__1; ++j) {
/* Computing MAX */
	i__2 = nmax, i__3 = nn[j];
	nmax = max(i__2,i__3);
	if (nn[j] < 0) {
	    badnn = TRUE_;
	}
/* L10: */
    }

    badnnb = FALSE_;
    kmax = 0;
    i__1 = *nsizes;
    for (j = 1; j <= i__1; ++j) {
/* Computing MAX */
	i__2 = kmax, i__3 = kk[j];
	kmax = max(i__2,i__3);
	if (kk[j] < 0) {
	    badnnb = TRUE_;
	}
/* L20: */
    }
/* Computing MIN */
    i__1 = nmax - 1;
    kmax = min(i__1,kmax);

/*     Check for errors */

    if (*nsizes < 0) {
	*info = -1;
    } else if (badnn) {
	*info = -2;
    } else if (*nwdths < 0) {
	*info = -3;
    } else if (badnnb) {
	*info = -4;
    } else if (*ntypes < 0) {
	*info = -5;
    } else if (*lda < kmax + 1) {
	*info = -11;
    } else if (*ldu < nmax) {
	*info = -15;
    } else if ((max(*lda,nmax) + 1) * nmax > *lwork) {
	*info = -17;
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CCHKHB", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*nsizes == 0 || *ntypes == 0 || *nwdths == 0) {
	return 0;
    }

/*     More Important constants */

    unfl = slamch_("Safe minimum");
    ovfl = 1.f / unfl;
    ulp = slamch_("Epsilon") * slamch_("Base");
    ulpinv = 1.f / ulp;
    rtunfl = sqrt(unfl);
    rtovfl = sqrt(ovfl);

/*     Loop over sizes, types */

    nerrs = 0;
    nmats = 0;

    i__1 = *nsizes;
    for (jsize = 1; jsize <= i__1; ++jsize) {
	n = nn[jsize];
	aninv = 1.f / (real) max(1,n);

	i__2 = *nwdths;
	for (jwidth = 1; jwidth <= i__2; ++jwidth) {
	    k = kk[jwidth];
	    if (k > n) {
		goto L180;
	    }
/* Computing MAX */
/* Computing MIN */
	    i__5 = n - 1;
	    i__3 = 0, i__4 = min(i__5,k);
	    k = max(i__3,i__4);

	    if (*nsizes != 1) {
		mtypes = min(15,*ntypes);
	    } else {
		mtypes = min(16,*ntypes);
	    }

	    i__3 = mtypes;
	    for (jtype = 1; jtype <= i__3; ++jtype) {
		if (! dotype[jtype]) {
		    goto L170;
		}
		++nmats;
		ntest = 0;

		for (j = 1; j <= 4; ++j) {
		    ioldsd[j - 1] = iseed[j];
/* L30: */
		}

/*              Compute "A". */
/*              Store as "Upper"; later, we will copy to other format. */

/*              Control parameters: */

/*                  KMAGN  KMODE        KTYPE */
/*              =1  O(1)   clustered 1  zero */
/*              =2  large  clustered 2  identity */
/*              =3  small  exponential  (none) */
/*              =4         arithmetic   diagonal, (w/ eigenvalues) */
/*              =5         random log   hermitian, w/ eigenvalues */
/*              =6         random       (none) */
/*              =7                      random diagonal */
/*              =8                      random hermitian */
/*              =9                      positive definite */
/*              =10                     diagonally dominant tridiagonal */

		if (mtypes > 15) {
		    goto L100;
		}

		itype = ktype[jtype - 1];
		imode = kmode[jtype - 1];

/*              Compute norm */

		switch (kmagn[jtype - 1]) {
		    case 1:  goto L40;
		    case 2:  goto L50;
		    case 3:  goto L60;
		}

L40:
		anorm = 1.f;
		goto L70;

L50:
		anorm = rtovfl * ulp * aninv;
		goto L70;

L60:
		anorm = rtunfl * n * ulpinv;
		goto L70;

L70:

		claset_("Full", lda, &n, &c_b1, &c_b1, &a[a_offset], lda);
		iinfo = 0;
		if (jtype <= 15) {
		    cond = ulpinv;
		} else {
		    cond = ulpinv * aninv / 10.f;
		}

/*              Special Matrices -- Identity & Jordan block */

/*                 Zero */

		if (itype == 1) {
		    iinfo = 0;

		} else if (itype == 2) {

/*                 Identity */

		    i__4 = n;
		    for (jcol = 1; jcol <= i__4; ++jcol) {
			i__5 = k + 1 + jcol * a_dim1;
			a[i__5].r = anorm, a[i__5].i = 0.f;
/* L80: */
		    }

		} else if (itype == 4) {

/*                 Diagonal Matrix, [Eigen]values Specified */

		    clatms_(&n, &n, "S", &iseed[1], "H", &rwork[1], &imode, &
			    cond, &anorm, &c__0, &c__0, "Q", &a[k + 1 + 
			    a_dim1], lda, &work[1], &iinfo);

		} else if (itype == 5) {

/*                 Hermitian, eigenvalues specified */

		    clatms_(&n, &n, "S", &iseed[1], "H", &rwork[1], &imode, &
			    cond, &anorm, &k, &k, "Q", &a[a_offset], lda, &
			    work[1], &iinfo);

		} else if (itype == 7) {

/*                 Diagonal, random eigenvalues */

		    clatmr_(&n, &n, "S", &iseed[1], "H", &work[1], &c__6, &
			    c_b32, &c_b2, "T", "N", &work[n + 1], &c__1, &
			    c_b32, &work[(n << 1) + 1], &c__1, &c_b32, "N", 
			    idumma, &c__0, &c__0, &c_b42, &anorm, "Q", &a[k + 
			    1 + a_dim1], lda, idumma, &iinfo);

		} else if (itype == 8) {

/*                 Hermitian, random eigenvalues */

		    clatmr_(&n, &n, "S", &iseed[1], "H", &work[1], &c__6, &
			    c_b32, &c_b2, "T", "N", &work[n + 1], &c__1, &
			    c_b32, &work[(n << 1) + 1], &c__1, &c_b32, "N", 
			    idumma, &k, &k, &c_b42, &anorm, "Q", &a[a_offset], 
			     lda, idumma, &iinfo);

		} else if (itype == 9) {

/*                 Positive definite, eigenvalues specified. */

		    clatms_(&n, &n, "S", &iseed[1], "P", &rwork[1], &imode, &
			    cond, &anorm, &k, &k, "Q", &a[a_offset], lda, &
			    work[n + 1], &iinfo);

		} else if (itype == 10) {

/*                 Positive definite tridiagonal, eigenvalues specified. */

		    if (n > 1) {
			k = max(1,k);
		    }
		    clatms_(&n, &n, "S", &iseed[1], "P", &rwork[1], &imode, &
			    cond, &anorm, &c__1, &c__1, "Q", &a[k + a_dim1], 
			    lda, &work[1], &iinfo);
		    i__4 = n;
		    for (i__ = 2; i__ <= i__4; ++i__) {
			i__5 = k + 1 + (i__ - 1) * a_dim1;
			i__6 = k + 1 + i__ * a_dim1;
			q__1.r = a[i__5].r * a[i__6].r - a[i__5].i * a[i__6]
				.i, q__1.i = a[i__5].r * a[i__6].i + a[i__5]
				.i * a[i__6].r;
			temp1 = c_abs(&a[k + i__ * a_dim1]) / sqrt(c_abs(&
				q__1));
			if (temp1 > .5f) {
			    i__5 = k + i__ * a_dim1;
			    i__6 = k + 1 + (i__ - 1) * a_dim1;
			    i__7 = k + 1 + i__ * a_dim1;
			    q__1.r = a[i__6].r * a[i__7].r - a[i__6].i * a[
				    i__7].i, q__1.i = a[i__6].r * a[i__7].i + 
				    a[i__6].i * a[i__7].r;
			    r__1 = sqrt(c_abs(&q__1)) * .5f;
			    a[i__5].r = r__1, a[i__5].i = 0.f;
			}
/* L90: */
		    }

		} else {

		    iinfo = 1;
		}

		if (iinfo != 0) {
		    io___36.ciunit = *nounit;
		    s_wsfe(&io___36);
		    do_fio(&c__1, "Generator", (ftnlen)9);
		    do_fio(&c__1, (char *)&iinfo, (ftnlen)sizeof(integer));
		    do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer));
		    do_fio(&c__1, (char *)&jtype, (ftnlen)sizeof(integer));
		    do_fio(&c__4, (char *)&ioldsd[0], (ftnlen)sizeof(integer))
			    ;
		    e_wsfe();
		    *info = abs(iinfo);
		    return 0;
		}

L100:

/*              Call CHBTRD to compute S and U from upper triangle. */

		i__4 = k + 1;
		clacpy_(" ", &i__4, &n, &a[a_offset], lda, &work[1], lda);

		ntest = 1;
		chbtrd_("V", "U", &n, &k, &work[1], lda, &sd[1], &se[1], &u[
			u_offset], ldu, &work[*lda * n + 1], &iinfo);

		if (iinfo != 0) {
		    io___37.ciunit = *nounit;
		    s_wsfe(&io___37);
		    do_fio(&c__1, "CHBTRD(U)", (ftnlen)9);
		    do_fio(&c__1, (char *)&iinfo, (ftnlen)sizeof(integer));
		    do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer));
		    do_fio(&c__1, (char *)&jtype, (ftnlen)sizeof(integer));
		    do_fio(&c__4, (char *)&ioldsd[0], (ftnlen)sizeof(integer))
			    ;
		    e_wsfe();
		    *info = abs(iinfo);
		    if (iinfo < 0) {
			return 0;
		    } else {
			result[1] = ulpinv;
			goto L150;
		    }
		}

/*              Do tests 1 and 2 */

		chbt21_("Upper", &n, &k, &c__1, &a[a_offset], lda, &sd[1], &
			se[1], &u[u_offset], ldu, &work[1], &rwork[1], &
			result[1]);

/*              Convert A from Upper-Triangle-Only storage to */
/*              Lower-Triangle-Only storage. */

		i__4 = n;
		for (jc = 1; jc <= i__4; ++jc) {
/* Computing MIN */
		    i__6 = k, i__7 = n - jc;
		    i__5 = min(i__6,i__7);
		    for (jr = 0; jr <= i__5; ++jr) {
			i__6 = jr + 1 + jc * a_dim1;
			r_cnjg(&q__1, &a[k + 1 - jr + (jc + jr) * a_dim1]);
			a[i__6].r = q__1.r, a[i__6].i = q__1.i;
/* L110: */
		    }
/* L120: */
		}
		i__4 = n;
		for (jc = n + 1 - k; jc <= i__4; ++jc) {
/* Computing MIN */
		    i__5 = k, i__6 = n - jc;
		    i__7 = k;
		    for (jr = min(i__5,i__6) + 1; jr <= i__7; ++jr) {
			i__5 = jr + 1 + jc * a_dim1;
			a[i__5].r = 0.f, a[i__5].i = 0.f;
/* L130: */
		    }
/* L140: */
		}

/*              Call CHBTRD to compute S and U from lower triangle */

		i__4 = k + 1;
		clacpy_(" ", &i__4, &n, &a[a_offset], lda, &work[1], lda);

		ntest = 3;
		chbtrd_("V", "L", &n, &k, &work[1], lda, &sd[1], &se[1], &u[
			u_offset], ldu, &work[*lda * n + 1], &iinfo);

		if (iinfo != 0) {
		    io___40.ciunit = *nounit;
		    s_wsfe(&io___40);
		    do_fio(&c__1, "CHBTRD(L)", (ftnlen)9);
		    do_fio(&c__1, (char *)&iinfo, (ftnlen)sizeof(integer));
		    do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer));
		    do_fio(&c__1, (char *)&jtype, (ftnlen)sizeof(integer));
		    do_fio(&c__4, (char *)&ioldsd[0], (ftnlen)sizeof(integer))
			    ;
		    e_wsfe();
		    *info = abs(iinfo);
		    if (iinfo < 0) {
			return 0;
		    } else {
			result[3] = ulpinv;
			goto L150;
		    }
		}
		ntest = 4;

/*              Do tests 3 and 4 */

		chbt21_("Lower", &n, &k, &c__1, &a[a_offset], lda, &sd[1], &
			se[1], &u[u_offset], ldu, &work[1], &rwork[1], &
			result[3]);

/*              End of Loop -- Check for RESULT(j) > THRESH */

L150:
		ntestt += ntest;

/*              Print out tests which fail. */

		i__4 = ntest;
		for (jr = 1; jr <= i__4; ++jr) {
		    if (result[jr] >= *thresh) {

/*                    If this is the first test to fail, */
/*                    print a header to the data file. */

			if (nerrs == 0) {
			    io___41.ciunit = *nounit;
			    s_wsfe(&io___41);
			    do_fio(&c__1, "CHB", (ftnlen)3);
			    e_wsfe();
			    io___42.ciunit = *nounit;
			    s_wsfe(&io___42);
			    e_wsfe();
			    io___43.ciunit = *nounit;
			    s_wsfe(&io___43);
			    e_wsfe();
			    io___44.ciunit = *nounit;
			    s_wsfe(&io___44);
			    do_fio(&c__1, "Hermitian", (ftnlen)9);
			    e_wsfe();
			    io___45.ciunit = *nounit;
			    s_wsfe(&io___45);
			    do_fio(&c__1, "unitary", (ftnlen)7);
			    do_fio(&c__1, "*", (ftnlen)1);
			    do_fio(&c__1, "conjugate transpose", (ftnlen)19);
			    for (j = 1; j <= 4; ++j) {
				do_fio(&c__1, "*", (ftnlen)1);
			    }
			    e_wsfe();
			}
			++nerrs;
			io___46.ciunit = *nounit;
			s_wsfe(&io___46);
			do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer));
			do_fio(&c__1, (char *)&k, (ftnlen)sizeof(integer));
			do_fio(&c__4, (char *)&ioldsd[0], (ftnlen)sizeof(
				integer));
			do_fio(&c__1, (char *)&jtype, (ftnlen)sizeof(integer))
				;
			do_fio(&c__1, (char *)&jr, (ftnlen)sizeof(integer));
			do_fio(&c__1, (char *)&result[jr], (ftnlen)sizeof(
				real));
			e_wsfe();
		    }
/* L160: */
		}

L170:
		;
	    }
L180:
	    ;
	}
/* L190: */
    }

/*     Summary */

    slasum_("CHB", nounit, &nerrs, &ntestt);
    return 0;




/*     End of CCHKHB */

} /* cchkhb_ */
Esempio n. 8
0
/* Subroutine */ int chbgv_(char *jobz, char *uplo, integer *n, integer *ka, 
	integer *kb, complex *ab, integer *ldab, complex *bb, integer *ldbb, 
	real *w, complex *z, integer *ldz, complex *work, real *rwork, 
	integer *info)
{
/*  -- LAPACK driver routine (version 2.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       September 30, 1994   


    Purpose   
    =======   

    CHBGV computes all the eigenvalues, and optionally, the eigenvectors 
  
    of a complex generalized Hermitian-definite banded eigenproblem, of   
    the form A*x=(lambda)*B*x. Here A and B are assumed to be Hermitian   
    and banded, and B is also positive definite.   

    Arguments   
    =========   

    JOBZ    (input) CHARACTER*1   
            = 'N':  Compute eigenvalues only;   
            = 'V':  Compute eigenvalues and eigenvectors.   

    UPLO    (input) CHARACTER*1   
            = 'U':  Upper triangles of A and B are stored;   
            = 'L':  Lower triangles of A and B are stored.   

    N       (input) INTEGER   
            The order of the matrices A and B.  N >= 0.   

    KA      (input) INTEGER   
            The number of superdiagonals of the matrix A if UPLO = 'U',   
            or the number of subdiagonals if UPLO = 'L'. KA >= 0.   

    KB      (input) INTEGER   
            The number of superdiagonals of the matrix B if UPLO = 'U',   
            or the number of subdiagonals if UPLO = 'L'. KB >= 0.   

    AB      (input/output) COMPLEX array, dimension (LDAB, N)   
            On entry, the upper or lower triangle of the Hermitian band   
            matrix A, stored in the first ka+1 rows of the array.  The   
            j-th column of A is stored in the j-th column of the array AB 
  
            as follows:   
            if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-ka)<=i<=j; 
  
            if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+ka). 
  

            On exit, the contents of AB are destroyed.   

    LDAB    (input) INTEGER   
            The leading dimension of the array AB.  LDAB >= KA+1.   

    BB      (input/output) COMPLEX array, dimension (LDBB, N)   
            On entry, the upper or lower triangle of the Hermitian band   
            matrix B, stored in the first kb+1 rows of the array.  The   
            j-th column of B is stored in the j-th column of the array BB 
  
            as follows:   
            if UPLO = 'U', BB(kb+1+i-j,j) = B(i,j) for max(1,j-kb)<=i<=j; 
  
            if UPLO = 'L', BB(1+i-j,j)    = B(i,j) for j<=i<=min(n,j+kb). 
  

            On exit, the factor S from the split Cholesky factorization   
            B = S**H*S, as returned by CPBSTF.   

    LDBB    (input) INTEGER   
            The leading dimension of the array BB.  LDBB >= KB+1.   

    W       (output) REAL array, dimension (N)   
            If INFO = 0, the eigenvalues in ascending order.   

    Z       (output) COMPLEX array, dimension (LDZ, N)   
            If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of   
            eigenvectors, with the i-th column of Z holding the   
            eigenvector associated with W(i). The eigenvectors are   
            normalized so that Z**H*B*Z = I.   
            If JOBZ = 'N', then Z is not referenced.   

    LDZ     (input) INTEGER   
            The leading dimension of the array Z.  LDZ >= 1, and if   
            JOBZ = 'V', LDZ >= N.   

    WORK    (workspace) COMPLEX array, dimension (N)   

    RWORK   (workspace) REAL array, dimension (3*N)   

    INFO    (output) INTEGER   
            = 0:  successful exit   
            < 0:  if INFO = -i, the i-th argument had an illegal value   
            > 0:  if INFO = i, and i is:   
               <= N:  the algorithm failed to converge:   
                      i off-diagonal elements of an intermediate   
                      tridiagonal form did not converge to zero;   
               > N:   if INFO = N + i, for 1 <= i <= N, then CPBSTF   
                      returned INFO = i: B is not positive definite.   
                      The factorization of B could not be completed and   
                      no eigenvalues or eigenvectors were computed.   

    ===================================================================== 
  


       Test the input parameters.   

    
   Parameter adjustments   
       Function Body */
    /* System generated locals */
    integer ab_dim1, ab_offset, bb_dim1, bb_offset, z_dim1, z_offset, i__1;
    /* Local variables */
    static integer inde;
    static char vect[1];
    extern logical lsame_(char *, char *);
    static integer iinfo;
    static logical upper, wantz;
    extern /* Subroutine */ int chbtrd_(char *, char *, integer *, integer *, 
	    complex *, integer *, real *, real *, complex *, integer *, 
	    complex *, integer *), chbgst_(char *, char *, 
	    integer *, integer *, integer *, complex *, integer *, complex *, 
	    integer *, complex *, integer *, complex *, real *, integer *), xerbla_(char *, integer *), cpbstf_(char 
	    *, integer *, integer *, complex *, integer *, integer *);
    static integer indwrk;
    extern /* Subroutine */ int csteqr_(char *, integer *, real *, real *, 
	    complex *, integer *, real *, integer *), ssterf_(integer 
	    *, real *, real *, integer *);


#define W(I) w[(I)-1]
#define WORK(I) work[(I)-1]
#define RWORK(I) rwork[(I)-1]

#define AB(I,J) ab[(I)-1 + ((J)-1)* ( *ldab)]
#define BB(I,J) bb[(I)-1 + ((J)-1)* ( *ldbb)]
#define Z(I,J) z[(I)-1 + ((J)-1)* ( *ldz)]

    wantz = lsame_(jobz, "V");
    upper = lsame_(uplo, "U");

    *info = 0;
    if (! (wantz || lsame_(jobz, "N"))) {
	*info = -1;
    } else if (! (upper || lsame_(uplo, "L"))) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (*ka < 0) {
	*info = -4;
    } else if (*kb < 0 || *kb > *ka) {
	*info = -5;
    } else if (*ldab < *ka + 1) {
	*info = -7;
    } else if (*ldbb < *kb + 1) {
	*info = -9;
    } else if (*ldz < 1 || wantz && *ldz < *n) {
	*info = -12;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHBGV ", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*n == 0) {
	return 0;
    }

/*     Form a split Cholesky factorization of B. */

    cpbstf_(uplo, n, kb, &BB(1,1), ldbb, info);
    if (*info != 0) {
	*info = *n + *info;
	return 0;
    }

/*     Transform problem to standard eigenvalue problem. */

    inde = 1;
    indwrk = inde + *n;
    chbgst_(jobz, uplo, n, ka, kb, &AB(1,1), ldab, &BB(1,1), ldbb,
	     &Z(1,1), ldz, &WORK(1), &RWORK(indwrk), &iinfo);

/*     Reduce to tridiagonal form. */

    if (wantz) {
	*(unsigned char *)vect = 'U';
    } else {
	*(unsigned char *)vect = 'N';
    }
    chbtrd_(vect, uplo, n, ka, &AB(1,1), ldab, &W(1), &RWORK(inde), &Z(1,1), ldz, &WORK(1), &iinfo);

/*     For eigenvalues only, call SSTERF.  For eigenvectors, call CSTEQR. 
*/

    if (! wantz) {
	ssterf_(n, &W(1), &RWORK(inde), info);
    } else {
	csteqr_(jobz, n, &W(1), &RWORK(inde), &Z(1,1), ldz, &RWORK(
		indwrk), info);
    }
    return 0;

/*     End of CHBGV */

} /* chbgv_ */
Esempio n. 9
0
/* Subroutine */ int chbgvx_(char *jobz, char *range, char *uplo, integer *n, 
	integer *ka, integer *kb, complex *ab, integer *ldab, complex *bb, 
	integer *ldbb, complex *q, integer *ldq, real *vl, real *vu, integer *
	il, integer *iu, real *abstol, integer *m, real *w, complex *z__, 
	integer *ldz, complex *work, real *rwork, integer *iwork, integer *
	ifail, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, bb_dim1, bb_offset, q_dim1, q_offset, z_dim1, 
	    z_offset, i__1, i__2;

    /* Local variables */
    integer i__, j, jj;
    real tmp1;
    integer indd, inde;
    char vect[1];
    logical test;
    integer itmp1, indee;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */ int cgemv_(char *, integer *, integer *, complex *
, complex *, integer *, complex *, integer *, complex *, complex *
, integer *);
    integer iinfo;
    char order[1];
    extern /* Subroutine */ int ccopy_(integer *, complex *, integer *, 
	    complex *, integer *), cswap_(integer *, complex *, integer *, 
	    complex *, integer *);
    logical upper;
    extern /* Subroutine */ int scopy_(integer *, real *, integer *, real *, 
	    integer *);
    logical wantz, alleig, indeig;
    integer indibl;
    extern /* Subroutine */ int chbtrd_(char *, char *, integer *, integer *, 
	    complex *, integer *, real *, real *, complex *, integer *, 
	    complex *, integer *);
    logical valeig;
    extern /* Subroutine */ int chbgst_(char *, char *, integer *, integer *, 
	    integer *, complex *, integer *, complex *, integer *, complex *, 
	    integer *, complex *, real *, integer *), clacpy_(
	    char *, integer *, integer *, complex *, integer *, complex *, 
	    integer *), xerbla_(char *, integer *), cpbstf_(
	    char *, integer *, integer *, complex *, integer *, integer *);
    integer indiwk, indisp;
    extern /* Subroutine */ int cstein_(integer *, real *, real *, integer *, 
	    real *, integer *, integer *, complex *, integer *, real *, 
	    integer *, integer *, integer *);
    integer indrwk, indwrk;
    extern /* Subroutine */ int csteqr_(char *, integer *, real *, real *, 
	    complex *, integer *, real *, integer *), ssterf_(integer 
	    *, real *, real *, integer *);
    integer nsplit;
    extern /* Subroutine */ int sstebz_(char *, char *, integer *, real *, 
	    real *, integer *, integer *, real *, real *, real *, integer *, 
	    integer *, real *, integer *, integer *, real *, integer *, 
	    integer *);


/*  -- LAPACK driver routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  CHBGVX computes all the eigenvalues, and optionally, the eigenvectors */
/*  of a complex generalized Hermitian-definite banded eigenproblem, of */
/*  the form A*x=(lambda)*B*x. Here A and B are assumed to be Hermitian */
/*  and banded, and B is also positive definite.  Eigenvalues and */
/*  eigenvectors can be selected by specifying either all eigenvalues, */
/*  a range of values or a range of indices for the desired eigenvalues. */

/*  Arguments */
/*  ========= */

/*  JOBZ    (input) CHARACTER*1 */
/*          = 'N':  Compute eigenvalues only; */
/*          = 'V':  Compute eigenvalues and eigenvectors. */

/*  RANGE   (input) CHARACTER*1 */
/*          = 'A': all eigenvalues will be found; */
/*          = 'V': all eigenvalues in the half-open interval (VL,VU] */
/*                 will be found; */
/*          = 'I': the IL-th through IU-th eigenvalues will be found. */

/*  UPLO    (input) CHARACTER*1 */
/*          = 'U':  Upper triangles of A and B are stored; */
/*          = 'L':  Lower triangles of A and B are stored. */

/*  N       (input) INTEGER */
/*          The order of the matrices A and B.  N >= 0. */

/*  KA      (input) INTEGER */
/*          The number of superdiagonals of the matrix A if UPLO = 'U', */
/*          or the number of subdiagonals if UPLO = 'L'. KA >= 0. */

/*  KB      (input) INTEGER */
/*          The number of superdiagonals of the matrix B if UPLO = 'U', */
/*          or the number of subdiagonals if UPLO = 'L'. KB >= 0. */

/*  AB      (input/output) COMPLEX array, dimension (LDAB, N) */
/*          On entry, the upper or lower triangle of the Hermitian band */
/*          matrix A, stored in the first ka+1 rows of the array.  The */
/*          j-th column of A is stored in the j-th column of the array AB */
/*          as follows: */
/*          if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-ka)<=i<=j; */
/*          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+ka). */

/*          On exit, the contents of AB are destroyed. */

/*  LDAB    (input) INTEGER */
/*          The leading dimension of the array AB.  LDAB >= KA+1. */

/*  BB      (input/output) COMPLEX array, dimension (LDBB, N) */
/*          On entry, the upper or lower triangle of the Hermitian band */
/*          matrix B, stored in the first kb+1 rows of the array.  The */
/*          j-th column of B is stored in the j-th column of the array BB */
/*          as follows: */
/*          if UPLO = 'U', BB(kb+1+i-j,j) = B(i,j) for max(1,j-kb)<=i<=j; */
/*          if UPLO = 'L', BB(1+i-j,j)    = B(i,j) for j<=i<=min(n,j+kb). */

/*          On exit, the factor S from the split Cholesky factorization */
/*          B = S**H*S, as returned by CPBSTF. */

/*  LDBB    (input) INTEGER */
/*          The leading dimension of the array BB.  LDBB >= KB+1. */

/*  Q       (output) COMPLEX array, dimension (LDQ, N) */
/*          If JOBZ = 'V', the n-by-n matrix used in the reduction of */
/*          A*x = (lambda)*B*x to standard form, i.e. C*x = (lambda)*x, */
/*          and consequently C to tridiagonal form. */
/*          If JOBZ = 'N', the array Q is not referenced. */

/*  LDQ     (input) INTEGER */
/*          The leading dimension of the array Q.  If JOBZ = 'N', */
/*          LDQ >= 1. If JOBZ = 'V', LDQ >= max(1,N). */

/*  VL      (input) REAL */
/*  VU      (input) REAL */
/*          If RANGE='V', the lower and upper bounds of the interval to */
/*          be searched for eigenvalues. VL < VU. */
/*          Not referenced if RANGE = 'A' or 'I'. */

/*  IL      (input) INTEGER */
/*  IU      (input) INTEGER */
/*          If RANGE='I', the indices (in ascending order) of the */
/*          smallest and largest eigenvalues to be returned. */
/*          1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. */
/*          Not referenced if RANGE = 'A' or 'V'. */

/*  ABSTOL  (input) REAL */
/*          The absolute error tolerance for the eigenvalues. */
/*          An approximate eigenvalue is accepted as converged */
/*          when it is determined to lie in an interval [a,b] */
/*          of width less than or equal to */

/*                  ABSTOL + EPS *   max( |a|,|b| ) , */

/*          where EPS is the machine precision.  If ABSTOL is less than */
/*          or equal to zero, then  EPS*|T|  will be used in its place, */
/*          where |T| is the 1-norm of the tridiagonal matrix obtained */
/*          by reducing AP to tridiagonal form. */

/*          Eigenvalues will be computed most accurately when ABSTOL is */
/*          set to twice the underflow threshold 2*SLAMCH('S'), not zero. */
/*          If this routine returns with INFO>0, indicating that some */
/*          eigenvectors did not converge, try setting ABSTOL to */
/*          2*SLAMCH('S'). */

/*  M       (output) INTEGER */
/*          The total number of eigenvalues found.  0 <= M <= N. */
/*          If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1. */

/*  W       (output) REAL array, dimension (N) */
/*          If INFO = 0, the eigenvalues in ascending order. */

/*  Z       (output) COMPLEX array, dimension (LDZ, N) */
/*          If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of */
/*          eigenvectors, with the i-th column of Z holding the */
/*          eigenvector associated with W(i). The eigenvectors are */
/*          normalized so that Z**H*B*Z = I. */
/*          If JOBZ = 'N', then Z is not referenced. */

/*  LDZ     (input) INTEGER */
/*          The leading dimension of the array Z.  LDZ >= 1, and if */
/*          JOBZ = 'V', LDZ >= N. */

/*  WORK    (workspace) COMPLEX array, dimension (N) */

/*  RWORK   (workspace) REAL array, dimension (7*N) */

/*  IWORK   (workspace) INTEGER array, dimension (5*N) */

/*  IFAIL   (output) INTEGER array, dimension (N) */
/*          If JOBZ = 'V', then if INFO = 0, the first M elements of */
/*          IFAIL are zero.  If INFO > 0, then IFAIL contains the */
/*          indices of the eigenvectors that failed to converge. */
/*          If JOBZ = 'N', then IFAIL is not referenced. */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value */
/*          > 0:  if INFO = i, and i is: */
/*             <= N:  then i eigenvectors failed to converge.  Their */
/*                    indices are stored in array IFAIL. */
/*             > N:   if INFO = N + i, for 1 <= i <= N, then CPBSTF */
/*                    returned INFO = i: B is not positive definite. */
/*                    The factorization of B could not be completed and */
/*                    no eigenvalues or eigenvectors were computed. */

/*  Further Details */
/*  =============== */

/*  Based on contributions by */
/*     Mark Fahey, Department of Mathematics, Univ. of Kentucky, USA */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input parameters. */

    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    bb_dim1 = *ldbb;
    bb_offset = 1 + bb_dim1;
    bb -= bb_offset;
    q_dim1 = *ldq;
    q_offset = 1 + q_dim1;
    q -= q_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --work;
    --rwork;
    --iwork;
    --ifail;

    /* Function Body */
    wantz = lsame_(jobz, "V");
    upper = lsame_(uplo, "U");
    alleig = lsame_(range, "A");
    valeig = lsame_(range, "V");
    indeig = lsame_(range, "I");

    *info = 0;
    if (! (wantz || lsame_(jobz, "N"))) {
	*info = -1;
    } else if (! (alleig || valeig || indeig)) {
	*info = -2;
    } else if (! (upper || lsame_(uplo, "L"))) {
	*info = -3;
    } else if (*n < 0) {
	*info = -4;
    } else if (*ka < 0) {
	*info = -5;
    } else if (*kb < 0 || *kb > *ka) {
	*info = -6;
    } else if (*ldab < *ka + 1) {
	*info = -8;
    } else if (*ldbb < *kb + 1) {
	*info = -10;
    } else if (*ldq < 1 || wantz && *ldq < *n) {
	*info = -12;
    } else {
	if (valeig) {
	    if (*n > 0 && *vu <= *vl) {
		*info = -14;
	    }
	} else if (indeig) {
	    if (*il < 1 || *il > max(1,*n)) {
		*info = -15;
	    } else if (*iu < min(*n,*il) || *iu > *n) {
		*info = -16;
	    }
	}
    }
    if (*info == 0) {
	if (*ldz < 1 || wantz && *ldz < *n) {
	    *info = -21;
	}
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHBGVX", &i__1);
	return 0;
    }

/*     Quick return if possible */

    *m = 0;
    if (*n == 0) {
	return 0;
    }

/*     Form a split Cholesky factorization of B. */

    cpbstf_(uplo, n, kb, &bb[bb_offset], ldbb, info);
    if (*info != 0) {
	*info = *n + *info;
	return 0;
    }

/*     Transform problem to standard eigenvalue problem. */

    chbgst_(jobz, uplo, n, ka, kb, &ab[ab_offset], ldab, &bb[bb_offset], ldbb, 
	     &q[q_offset], ldq, &work[1], &rwork[1], &iinfo);

/*     Solve the standard eigenvalue problem. */
/*     Reduce Hermitian band matrix to tridiagonal form. */

    indd = 1;
    inde = indd + *n;
    indrwk = inde + *n;
    indwrk = 1;
    if (wantz) {
	*(unsigned char *)vect = 'U';
    } else {
	*(unsigned char *)vect = 'N';
    }
    chbtrd_(vect, uplo, n, ka, &ab[ab_offset], ldab, &rwork[indd], &rwork[
	    inde], &q[q_offset], ldq, &work[indwrk], &iinfo);

/*     If all eigenvalues are desired and ABSTOL is less than or equal */
/*     to zero, then call SSTERF or CSTEQR.  If this fails for some */
/*     eigenvalue, then try SSTEBZ. */

    test = FALSE_;
    if (indeig) {
	if (*il == 1 && *iu == *n) {
	    test = TRUE_;
	}
    }
    if ((alleig || test) && *abstol <= 0.f) {
	scopy_(n, &rwork[indd], &c__1, &w[1], &c__1);
	indee = indrwk + (*n << 1);
	i__1 = *n - 1;
	scopy_(&i__1, &rwork[inde], &c__1, &rwork[indee], &c__1);
	if (! wantz) {
	    ssterf_(n, &w[1], &rwork[indee], info);
	} else {
	    clacpy_("A", n, n, &q[q_offset], ldq, &z__[z_offset], ldz);
	    csteqr_(jobz, n, &w[1], &rwork[indee], &z__[z_offset], ldz, &
		    rwork[indrwk], info);
	    if (*info == 0) {
		i__1 = *n;
		for (i__ = 1; i__ <= i__1; ++i__) {
		    ifail[i__] = 0;
/* L10: */
		}
	    }
	}
	if (*info == 0) {
	    *m = *n;
	    goto L30;
	}
	*info = 0;
    }

/*     Otherwise, call SSTEBZ and, if eigenvectors are desired, */
/*     call CSTEIN. */

    if (wantz) {
	*(unsigned char *)order = 'B';
    } else {
	*(unsigned char *)order = 'E';
    }
    indibl = 1;
    indisp = indibl + *n;
    indiwk = indisp + *n;
    sstebz_(range, order, n, vl, vu, il, iu, abstol, &rwork[indd], &rwork[
	    inde], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &rwork[
	    indrwk], &iwork[indiwk], info);

    if (wantz) {
	cstein_(n, &rwork[indd], &rwork[inde], m, &w[1], &iwork[indibl], &
		iwork[indisp], &z__[z_offset], ldz, &rwork[indrwk], &iwork[
		indiwk], &ifail[1], info);

/*        Apply unitary matrix used in reduction to tridiagonal */
/*        form to eigenvectors returned by CSTEIN. */

	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    ccopy_(n, &z__[j * z_dim1 + 1], &c__1, &work[1], &c__1);
	    cgemv_("N", n, n, &c_b2, &q[q_offset], ldq, &work[1], &c__1, &
		    c_b1, &z__[j * z_dim1 + 1], &c__1);
/* L20: */
	}
    }

L30:

/*     If eigenvalues are not in order, then sort them, along with */
/*     eigenvectors. */

    if (wantz) {
	i__1 = *m - 1;
	for (j = 1; j <= i__1; ++j) {
	    i__ = 0;
	    tmp1 = w[j];
	    i__2 = *m;
	    for (jj = j + 1; jj <= i__2; ++jj) {
		if (w[jj] < tmp1) {
		    i__ = jj;
		    tmp1 = w[jj];
		}
/* L40: */
	    }

	    if (i__ != 0) {
		itmp1 = iwork[indibl + i__ - 1];
		w[i__] = w[j];
		iwork[indibl + i__ - 1] = iwork[indibl + j - 1];
		w[j] = tmp1;
		iwork[indibl + j - 1] = itmp1;
		cswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[j * z_dim1 + 1], 
			 &c__1);
		if (*info != 0) {
		    itmp1 = ifail[i__];
		    ifail[i__] = ifail[j];
		    ifail[j] = itmp1;
		}
	    }
/* L50: */
	}
    }

    return 0;

/*     End of CHBGVX */

} /* chbgvx_ */
Esempio n. 10
0
/* Subroutine */ int chbevd_(char *jobz, char *uplo, integer *n, integer *kd, 
	complex *ab, integer *ldab, real *w, complex *z__, integer *ldz, 
	complex *work, integer *lwork, real *rwork, integer *lrwork, integer *
	iwork, integer *liwork, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, z_dim1, z_offset, i__1;
    real r__1;

    /* Builtin functions */
    double sqrt(doublereal);

    /* Local variables */
    real eps;
    integer inde;
    real anrm;
    integer imax;
    real rmin, rmax;
    integer llwk2;
    extern /* Subroutine */ int cgemm_(char *, char *, integer *, integer *, 
	    integer *, complex *, complex *, integer *, complex *, integer *, 
	    complex *, complex *, integer *);
    real sigma;
    extern logical lsame_(char *, char *);
    integer iinfo;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
    integer lwmin;
    logical lower;
    integer llrwk;
    logical wantz;
    integer indwk2;
    extern doublereal clanhb_(char *, char *, integer *, integer *, complex *, 
	     integer *, real *);
    integer iscale;
    extern /* Subroutine */ int clascl_(char *, integer *, integer *, real *, 
	    real *, integer *, integer *, complex *, integer *, integer *), cstedc_(char *, integer *, real *, real *, complex *, 
	    integer *, complex *, integer *, real *, integer *, integer *, 
	    integer *, integer *), chbtrd_(char *, char *, integer *, 
	    integer *, complex *, integer *, real *, real *, complex *, 
	    integer *, complex *, integer *);
    extern doublereal slamch_(char *);
    extern /* Subroutine */ int clacpy_(char *, integer *, integer *, complex 
	    *, integer *, complex *, integer *);
    real safmin;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    real bignum;
    integer indwrk, liwmin;
    extern /* Subroutine */ int ssterf_(integer *, real *, real *, integer *);
    integer lrwmin;
    real smlnum;
    logical lquery;


/*  -- LAPACK driver routine (version 3.1) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  CHBEVD computes all the eigenvalues and, optionally, eigenvectors of */
/*  a complex Hermitian band matrix A.  If eigenvectors are desired, it */
/*  uses a divide and conquer algorithm. */

/*  The divide and conquer algorithm makes very mild assumptions about */
/*  floating point arithmetic. It will work on machines with a guard */
/*  digit in add/subtract, or on those binary machines without guard */
/*  digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or */
/*  Cray-2. It could conceivably fail on hexadecimal or decimal machines */
/*  without guard digits, but we know of none. */

/*  Arguments */
/*  ========= */

/*  JOBZ    (input) CHARACTER*1 */
/*          = 'N':  Compute eigenvalues only; */
/*          = 'V':  Compute eigenvalues and eigenvectors. */

/*  UPLO    (input) CHARACTER*1 */
/*          = 'U':  Upper triangle of A is stored; */
/*          = 'L':  Lower triangle of A is stored. */

/*  N       (input) INTEGER */
/*          The order of the matrix A.  N >= 0. */

/*  KD      (input) INTEGER */
/*          The number of superdiagonals of the matrix A if UPLO = 'U', */
/*          or the number of subdiagonals if UPLO = 'L'.  KD >= 0. */

/*  AB      (input/output) COMPLEX array, dimension (LDAB, N) */
/*          On entry, the upper or lower triangle of the Hermitian band */
/*          matrix A, stored in the first KD+1 rows of the array.  The */
/*          j-th column of A is stored in the j-th column of the array AB */
/*          as follows: */
/*          if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; */
/*          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd). */

/*          On exit, AB is overwritten by values generated during the */
/*          reduction to tridiagonal form.  If UPLO = 'U', the first */
/*          superdiagonal and the diagonal of the tridiagonal matrix T */
/*          are returned in rows KD and KD+1 of AB, and if UPLO = 'L', */
/*          the diagonal and first subdiagonal of T are returned in the */
/*          first two rows of AB. */

/*  LDAB    (input) INTEGER */
/*          The leading dimension of the array AB.  LDAB >= KD + 1. */

/*  W       (output) REAL array, dimension (N) */
/*          If INFO = 0, the eigenvalues in ascending order. */

/*  Z       (output) COMPLEX array, dimension (LDZ, N) */
/*          If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal */
/*          eigenvectors of the matrix A, with the i-th column of Z */
/*          holding the eigenvector associated with W(i). */
/*          If JOBZ = 'N', then Z is not referenced. */

/*  LDZ     (input) INTEGER */
/*          The leading dimension of the array Z.  LDZ >= 1, and if */
/*          JOBZ = 'V', LDZ >= max(1,N). */

/*  WORK    (workspace/output) COMPLEX array, dimension (MAX(1,LWORK)) */
/*          On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */

/*  LWORK   (input) INTEGER */
/*          The dimension of the array WORK. */
/*          If N <= 1,               LWORK must be at least 1. */
/*          If JOBZ = 'N' and N > 1, LWORK must be at least N. */
/*          If JOBZ = 'V' and N > 1, LWORK must be at least 2*N**2. */

/*          If LWORK = -1, then a workspace query is assumed; the routine */
/*          only calculates the optimal sizes of the WORK, RWORK and */
/*          IWORK arrays, returns these values as the first entries of */
/*          the WORK, RWORK and IWORK arrays, and no error message */
/*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */

/*  RWORK   (workspace/output) REAL array, */
/*                                         dimension (LRWORK) */
/*          On exit, if INFO = 0, RWORK(1) returns the optimal LRWORK. */

/*  LRWORK  (input) INTEGER */
/*          The dimension of array RWORK. */
/*          If N <= 1,               LRWORK must be at least 1. */
/*          If JOBZ = 'N' and N > 1, LRWORK must be at least N. */
/*          If JOBZ = 'V' and N > 1, LRWORK must be at least */
/*                        1 + 5*N + 2*N**2. */

/*          If LRWORK = -1, then a workspace query is assumed; the */
/*          routine only calculates the optimal sizes of the WORK, RWORK */
/*          and IWORK arrays, returns these values as the first entries */
/*          of the WORK, RWORK and IWORK arrays, and no error message */
/*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */

/*  IWORK   (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) */
/*          On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK. */

/*  LIWORK  (input) INTEGER */
/*          The dimension of array IWORK. */
/*          If JOBZ = 'N' or N <= 1, LIWORK must be at least 1. */
/*          If JOBZ = 'V' and N > 1, LIWORK must be at least 3 + 5*N . */

/*          If LIWORK = -1, then a workspace query is assumed; the */
/*          routine only calculates the optimal sizes of the WORK, RWORK */
/*          and IWORK arrays, returns these values as the first entries */
/*          of the WORK, RWORK and IWORK arrays, and no error message */
/*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit. */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value. */
/*          > 0:  if INFO = i, the algorithm failed to converge; i */
/*                off-diagonal elements of an intermediate tridiagonal */
/*                form did not converge to zero. */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input parameters. */

    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --work;
    --rwork;
    --iwork;

    /* Function Body */
    wantz = lsame_(jobz, "V");
    lower = lsame_(uplo, "L");
    lquery = *lwork == -1 || *liwork == -1 || *lrwork == -1;

    *info = 0;
    if (*n <= 1) {
	lwmin = 1;
	lrwmin = 1;
	liwmin = 1;
    } else {
	if (wantz) {
/* Computing 2nd power */
	    i__1 = *n;
	    lwmin = i__1 * i__1 << 1;
/* Computing 2nd power */
	    i__1 = *n;
	    lrwmin = *n * 5 + 1 + (i__1 * i__1 << 1);
	    liwmin = *n * 5 + 3;
	} else {
	    lwmin = *n;
	    lrwmin = *n;
	    liwmin = 1;
	}
    }
    if (! (wantz || lsame_(jobz, "N"))) {
	*info = -1;
    } else if (! (lower || lsame_(uplo, "U"))) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (*kd < 0) {
	*info = -4;
    } else if (*ldab < *kd + 1) {
	*info = -6;
    } else if (*ldz < 1 || wantz && *ldz < *n) {
	*info = -9;
    }

    if (*info == 0) {
	work[1].r = (real) lwmin, work[1].i = 0.f;
	rwork[1] = (real) lrwmin;
	iwork[1] = liwmin;

	if (*lwork < lwmin && ! lquery) {
	    *info = -11;
	} else if (*lrwork < lrwmin && ! lquery) {
	    *info = -13;
	} else if (*liwork < liwmin && ! lquery) {
	    *info = -15;
	}
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHBEVD", &i__1);
	return 0;
    } else if (lquery) {
	return 0;
    }

/*     Quick return if possible */

    if (*n == 0) {
	return 0;
    }

    if (*n == 1) {
	i__1 = ab_dim1 + 1;
	w[1] = ab[i__1].r;
	if (wantz) {
	    i__1 = z_dim1 + 1;
	    z__[i__1].r = 1.f, z__[i__1].i = 0.f;
	}
	return 0;
    }

/*     Get machine constants. */

    safmin = slamch_("Safe minimum");
    eps = slamch_("Precision");
    smlnum = safmin / eps;
    bignum = 1.f / smlnum;
    rmin = sqrt(smlnum);
    rmax = sqrt(bignum);

/*     Scale matrix to allowable range, if necessary. */

    anrm = clanhb_("M", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]);
    iscale = 0;
    if (anrm > 0.f && anrm < rmin) {
	iscale = 1;
	sigma = rmin / anrm;
    } else if (anrm > rmax) {
	iscale = 1;
	sigma = rmax / anrm;
    }
    if (iscale == 1) {
	if (lower) {
	    clascl_("B", kd, kd, &c_b13, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	} else {
	    clascl_("Q", kd, kd, &c_b13, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	}
    }

/*     Call CHBTRD to reduce Hermitian band matrix to tridiagonal form. */

    inde = 1;
    indwrk = inde + *n;
    indwk2 = *n * *n + 1;
    llwk2 = *lwork - indwk2 + 1;
    llrwk = *lrwork - indwrk + 1;
    chbtrd_(jobz, uplo, n, kd, &ab[ab_offset], ldab, &w[1], &rwork[inde], &
	    z__[z_offset], ldz, &work[1], &iinfo);

/*     For eigenvalues only, call SSTERF.  For eigenvectors, call CSTEDC. */

    if (! wantz) {
	ssterf_(n, &w[1], &rwork[inde], info);
    } else {
	cstedc_("I", n, &w[1], &rwork[inde], &work[1], n, &work[indwk2], &
		llwk2, &rwork[indwrk], &llrwk, &iwork[1], liwork, info);
	cgemm_("N", "N", n, n, n, &c_b2, &z__[z_offset], ldz, &work[1], n, &
		c_b1, &work[indwk2], n);
	clacpy_("A", n, n, &work[indwk2], n, &z__[z_offset], ldz);
    }

/*     If matrix was scaled, then rescale eigenvalues appropriately. */

    if (iscale == 1) {
	if (*info == 0) {
	    imax = *n;
	} else {
	    imax = *info - 1;
	}
	r__1 = 1.f / sigma;
	sscal_(&imax, &r__1, &w[1], &c__1);
    }

    work[1].r = (real) lwmin, work[1].i = 0.f;
    rwork[1] = (real) lrwmin;
    iwork[1] = liwmin;
    return 0;

/*     End of CHBEVD */

} /* chbevd_ */