Beispiel #1
0
int
f2c_chpr2(char* uplo, integer* N,
          complex* alpha,
          complex* X, integer* incX,
          complex* Y, integer* incY,
          complex* Ap)
{
    chpr2_(uplo, N, alpha,
           X, incX, Y, incY, Ap);
    return 0;
}
Beispiel #2
0
void
chpr2(char uplo, int n, complex *alpha, complex *x, int incx, complex *y, int incy, complex *a )
{
   chpr2_( &uplo, &n, alpha, x, &incx, y, &incy, a );
}
Beispiel #3
0
/* Subroutine */ int chpgst_(integer *itype, char *uplo, integer *n, complex *
	ap, complex *bp, integer *info, ftnlen uplo_len)
{
    /* System generated locals */
    integer i__1, i__2, i__3, i__4;
    real r__1, r__2;
    complex q__1, q__2, q__3;

    /* Local variables */
    static integer j, k, j1, k1, jj, kk;
    static complex ct;
    static real ajj;
    static integer j1j1;
    static real akk;
    static integer k1k1;
    static real bjj, bkk;
    extern /* Subroutine */ int chpr2_(char *, integer *, complex *, complex *
	    , integer *, complex *, integer *, complex *, ftnlen);
    extern /* Complex */ VOID cdotc_(complex *, integer *, complex *, integer 
	    *, complex *, integer *);
    extern logical lsame_(char *, char *, ftnlen, ftnlen);
    extern /* Subroutine */ int chpmv_(char *, integer *, complex *, complex *
	    , complex *, integer *, complex *, complex *, integer *, ftnlen), 
	    caxpy_(integer *, complex *, complex *, integer *, complex *, 
	    integer *), ctpmv_(char *, char *, char *, integer *, complex *, 
	    complex *, integer *, ftnlen, ftnlen, ftnlen);
    static logical upper;
    extern /* Subroutine */ int ctpsv_(char *, char *, char *, integer *, 
	    complex *, complex *, integer *, ftnlen, ftnlen, ftnlen), csscal_(
	    integer *, real *, complex *, integer *), xerbla_(char *, integer 
	    *, ftnlen);


/*  -- LAPACK routine (version 3.0) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., */
/*     Courant Institute, Argonne National Lab, and Rice University */
/*     September 30, 1994 */

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

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

/*  CHPGST reduces a complex Hermitian-definite generalized */
/*  eigenproblem to standard form, using packed storage. */

/*  If ITYPE = 1, the problem is A*x = lambda*B*x, */
/*  and A is overwritten by inv(U**H)*A*inv(U) or inv(L)*A*inv(L**H) */

/*  If ITYPE = 2 or 3, the problem is A*B*x = lambda*x or */
/*  B*A*x = lambda*x, and A is overwritten by U*A*U**H or L**H*A*L. */

/*  B must have been previously factorized as U**H*U or L*L**H by CPPTRF. */

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

/*  ITYPE   (input) INTEGER */
/*          = 1: compute inv(U**H)*A*inv(U) or inv(L)*A*inv(L**H); */
/*          = 2 or 3: compute U*A*U**H or L**H*A*L. */

/*  UPLO    (input) CHARACTER */
/*          = 'U':  Upper triangle of A is stored and B is factored as */
/*                  U**H*U; */
/*          = 'L':  Lower triangle of A is stored and B is factored as */
/*                  L*L**H. */

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

/*  AP      (input/output) COMPLEX array, dimension (N*(N+1)/2) */
/*          On entry, the upper or lower triangle of the Hermitian matrix */
/*          A, packed columnwise in a linear array.  The j-th column of A */
/*          is stored in the array AP as follows: */
/*          if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; */
/*          if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n. */

/*          On exit, if INFO = 0, the transformed matrix, stored in the */
/*          same format as A. */

/*  BP      (input) COMPLEX array, dimension (N*(N+1)/2) */
/*          The triangular factor from the Cholesky factorization of B, */
/*          stored in the same format as A, as returned by CPPTRF. */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value */

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

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

/*     Test the input parameters. */

    /* Parameter adjustments */
    --bp;
    --ap;

    /* Function Body */
    *info = 0;
    upper = lsame_(uplo, "U", (ftnlen)1, (ftnlen)1);
    if (*itype < 1 || *itype > 3) {
	*info = -1;
    } else if (! upper && ! lsame_(uplo, "L", (ftnlen)1, (ftnlen)1)) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHPGST", &i__1, (ftnlen)6);
	return 0;
    }

    if (*itype == 1) {
	if (upper) {

/*           Compute inv(U')*A*inv(U) */

/*           J1 and JJ are the indices of A(1,j) and A(j,j) */

	    jj = 0;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		j1 = jj + 1;
		jj += j;

/*              Compute the j-th column of the upper triangle of A */

		i__2 = jj;
		i__3 = jj;
		r__1 = ap[i__3].r;
		ap[i__2].r = r__1, ap[i__2].i = 0.f;
		i__2 = jj;
		bjj = bp[i__2].r;
		ctpsv_(uplo, "Conjugate transpose", "Non-unit", &j, &bp[1], &
			ap[j1], &c__1, (ftnlen)1, (ftnlen)19, (ftnlen)8);
		i__2 = j - 1;
		q__1.r = -1.f, q__1.i = -0.f;
		chpmv_(uplo, &i__2, &q__1, &ap[1], &bp[j1], &c__1, &c_b1, &ap[
			j1], &c__1, (ftnlen)1);
		i__2 = j - 1;
		r__1 = 1.f / bjj;
		csscal_(&i__2, &r__1, &ap[j1], &c__1);
		i__2 = jj;
		i__3 = jj;
		i__4 = j - 1;
		cdotc_(&q__3, &i__4, &ap[j1], &c__1, &bp[j1], &c__1);
		q__2.r = ap[i__3].r - q__3.r, q__2.i = ap[i__3].i - q__3.i;
		q__1.r = q__2.r / bjj, q__1.i = q__2.i / bjj;
		ap[i__2].r = q__1.r, ap[i__2].i = q__1.i;
/* L10: */
	    }
	} else {

/*           Compute inv(L)*A*inv(L') */

/*           KK and K1K1 are the indices of A(k,k) and A(k+1,k+1) */

	    kk = 1;
	    i__1 = *n;
	    for (k = 1; k <= i__1; ++k) {
		k1k1 = kk + *n - k + 1;

/*              Update the lower triangle of A(k:n,k:n) */

		i__2 = kk;
		akk = ap[i__2].r;
		i__2 = kk;
		bkk = bp[i__2].r;
/* Computing 2nd power */
		r__1 = bkk;
		akk /= r__1 * r__1;
		i__2 = kk;
		ap[i__2].r = akk, ap[i__2].i = 0.f;
		if (k < *n) {
		    i__2 = *n - k;
		    r__1 = 1.f / bkk;
		    csscal_(&i__2, &r__1, &ap[kk + 1], &c__1);
		    r__1 = akk * -.5f;
		    ct.r = r__1, ct.i = 0.f;
		    i__2 = *n - k;
		    caxpy_(&i__2, &ct, &bp[kk + 1], &c__1, &ap[kk + 1], &c__1)
			    ;
		    i__2 = *n - k;
		    q__1.r = -1.f, q__1.i = -0.f;
		    chpr2_(uplo, &i__2, &q__1, &ap[kk + 1], &c__1, &bp[kk + 1]
			    , &c__1, &ap[k1k1], (ftnlen)1);
		    i__2 = *n - k;
		    caxpy_(&i__2, &ct, &bp[kk + 1], &c__1, &ap[kk + 1], &c__1)
			    ;
		    i__2 = *n - k;
		    ctpsv_(uplo, "No transpose", "Non-unit", &i__2, &bp[k1k1],
			     &ap[kk + 1], &c__1, (ftnlen)1, (ftnlen)12, (
			    ftnlen)8);
		}
		kk = k1k1;
/* L20: */
	    }
	}
    } else {
	if (upper) {

/*           Compute U*A*U' */

/*           K1 and KK are the indices of A(1,k) and A(k,k) */

	    kk = 0;
	    i__1 = *n;
	    for (k = 1; k <= i__1; ++k) {
		k1 = kk + 1;
		kk += k;

/*              Update the upper triangle of A(1:k,1:k) */

		i__2 = kk;
		akk = ap[i__2].r;
		i__2 = kk;
		bkk = bp[i__2].r;
		i__2 = k - 1;
		ctpmv_(uplo, "No transpose", "Non-unit", &i__2, &bp[1], &ap[
			k1], &c__1, (ftnlen)1, (ftnlen)12, (ftnlen)8);
		r__1 = akk * .5f;
		ct.r = r__1, ct.i = 0.f;
		i__2 = k - 1;
		caxpy_(&i__2, &ct, &bp[k1], &c__1, &ap[k1], &c__1);
		i__2 = k - 1;
		chpr2_(uplo, &i__2, &c_b1, &ap[k1], &c__1, &bp[k1], &c__1, &
			ap[1], (ftnlen)1);
		i__2 = k - 1;
		caxpy_(&i__2, &ct, &bp[k1], &c__1, &ap[k1], &c__1);
		i__2 = k - 1;
		csscal_(&i__2, &bkk, &ap[k1], &c__1);
		i__2 = kk;
/* Computing 2nd power */
		r__2 = bkk;
		r__1 = akk * (r__2 * r__2);
		ap[i__2].r = r__1, ap[i__2].i = 0.f;
/* L30: */
	    }
	} else {

/*           Compute L'*A*L */

/*           JJ and J1J1 are the indices of A(j,j) and A(j+1,j+1) */

	    jj = 1;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		j1j1 = jj + *n - j + 1;

/*              Compute the j-th column of the lower triangle of A */

		i__2 = jj;
		ajj = ap[i__2].r;
		i__2 = jj;
		bjj = bp[i__2].r;
		i__2 = jj;
		r__1 = ajj * bjj;
		i__3 = *n - j;
		cdotc_(&q__2, &i__3, &ap[jj + 1], &c__1, &bp[jj + 1], &c__1);
		q__1.r = r__1 + q__2.r, q__1.i = q__2.i;
		ap[i__2].r = q__1.r, ap[i__2].i = q__1.i;
		i__2 = *n - j;
		csscal_(&i__2, &bjj, &ap[jj + 1], &c__1);
		i__2 = *n - j;
		chpmv_(uplo, &i__2, &c_b1, &ap[j1j1], &bp[jj + 1], &c__1, &
			c_b1, &ap[jj + 1], &c__1, (ftnlen)1);
		i__2 = *n - j + 1;
		ctpmv_(uplo, "Conjugate transpose", "Non-unit", &i__2, &bp[jj]
			, &ap[jj], &c__1, (ftnlen)1, (ftnlen)19, (ftnlen)8);
		jj = j1j1;
/* L40: */
	    }
	}
    }
    return 0;

/*     End of CHPGST */

} /* chpgst_ */
Beispiel #4
0
/* Subroutine */ int chptrd_(char *uplo, integer *n, complex *ap, real *d__, 
	real *e, complex *tau, integer *info)
{
    /* System generated locals */
    integer i__1, i__2, i__3;
    real r__1;
    complex q__1, q__2, q__3, q__4;

    /* Local variables */
    integer i__, i1, ii, i1i1;
    complex taui;
    extern /* Subroutine */ int chpr2_(char *, integer *, complex *, complex *
, integer *, complex *, integer *, complex *);
    complex alpha;
    extern /* Complex */ VOID cdotc_(complex *, integer *, complex *, integer 
	    *, complex *, integer *);
    extern logical lsame_(char *, char *);
    extern /* Subroutine */ int chpmv_(char *, integer *, complex *, complex *
, complex *, integer *, complex *, complex *, integer *), 
	    caxpy_(integer *, complex *, complex *, integer *, complex *, 
	    integer *);
    logical upper;
    extern /* Subroutine */ int clarfg_(integer *, complex *, complex *, 
	    integer *, complex *), xerbla_(char *, integer *);


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

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

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

/*  CHPTRD reduces a complex Hermitian matrix A stored in packed form to */
/*  real symmetric tridiagonal form T by a unitary similarity */
/*  transformation: Q**H * A * Q = T. */

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

/*  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. */

/*  AP      (input/output) COMPLEX array, dimension (N*(N+1)/2) */
/*          On entry, the upper or lower triangle of the Hermitian matrix */
/*          A, packed columnwise in a linear array.  The j-th column of A */
/*          is stored in the array AP as follows: */
/*          if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; */
/*          if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n. */
/*          On exit, if UPLO = 'U', the diagonal and first superdiagonal */
/*          of A are overwritten by the corresponding elements of the */
/*          tridiagonal matrix T, and the elements above the first */
/*          superdiagonal, with the array TAU, represent the unitary */
/*          matrix Q as a product of elementary reflectors; if UPLO */
/*          = 'L', the diagonal and first subdiagonal of A are over- */
/*          written by the corresponding elements of the tridiagonal */
/*          matrix T, and the elements below the first subdiagonal, with */
/*          the array TAU, represent the unitary matrix Q as a product */
/*          of elementary reflectors. See Further Details. */

/*  D       (output) REAL array, dimension (N) */
/*          The diagonal elements of the tridiagonal matrix T: */
/*          D(i) = A(i,i). */

/*  E       (output) REAL array, dimension (N-1) */
/*          The off-diagonal elements of the tridiagonal matrix T: */
/*          E(i) = A(i,i+1) if UPLO = 'U', E(i) = A(i+1,i) if UPLO = 'L'. */

/*  TAU     (output) COMPLEX array, dimension (N-1) */
/*          The scalar factors of the elementary reflectors (see Further */
/*          Details). */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value */

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

/*  If UPLO = 'U', the matrix Q is represented as a product of elementary */
/*  reflectors */

/*     Q = H(n-1) . . . H(2) H(1). */

/*  Each H(i) has the form */

/*     H(i) = I - tau * v * v' */

/*  where tau is a complex scalar, and v is a complex vector with */
/*  v(i+1:n) = 0 and v(i) = 1; v(1:i-1) is stored on exit in AP, */
/*  overwriting A(1:i-1,i+1), and tau is stored in TAU(i). */

/*  If UPLO = 'L', the matrix Q is represented as a product of elementary */
/*  reflectors */

/*     Q = H(1) H(2) . . . H(n-1). */

/*  Each H(i) has the form */

/*     H(i) = I - tau * v * v' */

/*  where tau is a complex scalar, and v is a complex vector with */
/*  v(1:i) = 0 and v(i+1) = 1; v(i+2:n) is stored on exit in AP, */
/*  overwriting A(i+2:n,i), and tau is stored in TAU(i). */

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

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

/*     Test the input parameters */

    /* Parameter adjustments */
    --tau;
    --e;
    --d__;
    --ap;

    /* Function Body */
    *info = 0;
    upper = lsame_(uplo, "U");
    if (! upper && ! lsame_(uplo, "L")) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHPTRD", &i__1);
	return 0;
    }

/*     Quick return if possible */

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

    if (upper) {

/*        Reduce the upper triangle of A. */
/*        I1 is the index in AP of A(1,I+1). */

	i1 = *n * (*n - 1) / 2 + 1;
	i__1 = i1 + *n - 1;
	i__2 = i1 + *n - 1;
	r__1 = ap[i__2].r;
	ap[i__1].r = r__1, ap[i__1].i = 0.f;
	for (i__ = *n - 1; i__ >= 1; --i__) {

/*           Generate elementary reflector H(i) = I - tau * v * v' */
/*           to annihilate A(1:i-1,i+1) */

	    i__1 = i1 + i__ - 1;
	    alpha.r = ap[i__1].r, alpha.i = ap[i__1].i;
	    clarfg_(&i__, &alpha, &ap[i1], &c__1, &taui);
	    i__1 = i__;
	    e[i__1] = alpha.r;

	    if (taui.r != 0.f || taui.i != 0.f) {

/*              Apply H(i) from both sides to A(1:i,1:i) */

		i__1 = i1 + i__ - 1;
		ap[i__1].r = 1.f, ap[i__1].i = 0.f;

/*              Compute  y := tau * A * v  storing y in TAU(1:i) */

		chpmv_(uplo, &i__, &taui, &ap[1], &ap[i1], &c__1, &c_b2, &tau[
			1], &c__1);

/*              Compute  w := y - 1/2 * tau * (y'*v) * v */

		q__3.r = -.5f, q__3.i = -0.f;
		q__2.r = q__3.r * taui.r - q__3.i * taui.i, q__2.i = q__3.r * 
			taui.i + q__3.i * taui.r;
		cdotc_(&q__4, &i__, &tau[1], &c__1, &ap[i1], &c__1);
		q__1.r = q__2.r * q__4.r - q__2.i * q__4.i, q__1.i = q__2.r * 
			q__4.i + q__2.i * q__4.r;
		alpha.r = q__1.r, alpha.i = q__1.i;
		caxpy_(&i__, &alpha, &ap[i1], &c__1, &tau[1], &c__1);

/*              Apply the transformation as a rank-2 update: */
/*                 A := A - v * w' - w * v' */

		q__1.r = -1.f, q__1.i = -0.f;
		chpr2_(uplo, &i__, &q__1, &ap[i1], &c__1, &tau[1], &c__1, &ap[
			1]);

	    }
	    i__1 = i1 + i__ - 1;
	    i__2 = i__;
	    ap[i__1].r = e[i__2], ap[i__1].i = 0.f;
	    i__1 = i__ + 1;
	    i__2 = i1 + i__;
	    d__[i__1] = ap[i__2].r;
	    i__1 = i__;
	    tau[i__1].r = taui.r, tau[i__1].i = taui.i;
	    i1 -= i__;
/* L10: */
	}
	d__[1] = ap[1].r;
    } else {

/*        Reduce the lower triangle of A. II is the index in AP of */
/*        A(i,i) and I1I1 is the index of A(i+1,i+1). */

	ii = 1;
	r__1 = ap[1].r;
	ap[1].r = r__1, ap[1].i = 0.f;
	i__1 = *n - 1;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    i1i1 = ii + *n - i__ + 1;

/*           Generate elementary reflector H(i) = I - tau * v * v' */
/*           to annihilate A(i+2:n,i) */

	    i__2 = ii + 1;
	    alpha.r = ap[i__2].r, alpha.i = ap[i__2].i;
	    i__2 = *n - i__;
	    clarfg_(&i__2, &alpha, &ap[ii + 2], &c__1, &taui);
	    i__2 = i__;
	    e[i__2] = alpha.r;

	    if (taui.r != 0.f || taui.i != 0.f) {

/*              Apply H(i) from both sides to A(i+1:n,i+1:n) */

		i__2 = ii + 1;
		ap[i__2].r = 1.f, ap[i__2].i = 0.f;

/*              Compute  y := tau * A * v  storing y in TAU(i:n-1) */

		i__2 = *n - i__;
		chpmv_(uplo, &i__2, &taui, &ap[i1i1], &ap[ii + 1], &c__1, &
			c_b2, &tau[i__], &c__1);

/*              Compute  w := y - 1/2 * tau * (y'*v) * v */

		q__3.r = -.5f, q__3.i = -0.f;
		q__2.r = q__3.r * taui.r - q__3.i * taui.i, q__2.i = q__3.r * 
			taui.i + q__3.i * taui.r;
		i__2 = *n - i__;
		cdotc_(&q__4, &i__2, &tau[i__], &c__1, &ap[ii + 1], &c__1);
		q__1.r = q__2.r * q__4.r - q__2.i * q__4.i, q__1.i = q__2.r * 
			q__4.i + q__2.i * q__4.r;
		alpha.r = q__1.r, alpha.i = q__1.i;
		i__2 = *n - i__;
		caxpy_(&i__2, &alpha, &ap[ii + 1], &c__1, &tau[i__], &c__1);

/*              Apply the transformation as a rank-2 update: */
/*                 A := A - v * w' - w * v' */

		i__2 = *n - i__;
		q__1.r = -1.f, q__1.i = -0.f;
		chpr2_(uplo, &i__2, &q__1, &ap[ii + 1], &c__1, &tau[i__], &
			c__1, &ap[i1i1]);

	    }
	    i__2 = ii + 1;
	    i__3 = i__;
	    ap[i__2].r = e[i__3], ap[i__2].i = 0.f;
	    i__2 = i__;
	    i__3 = ii;
	    d__[i__2] = ap[i__3].r;
	    i__2 = i__;
	    tau[i__2].r = taui.r, tau[i__2].i = taui.i;
	    ii = i1i1;
/* L20: */
	}
	i__1 = *n;
	i__2 = ii;
	d__[i__1] = ap[i__2].r;
    }

    return 0;

/*     End of CHPTRD */

} /* chptrd_ */
Beispiel #5
0
/* Subroutine */
int chpgst_(integer *itype, char *uplo, integer *n, complex * ap, complex *bp, integer *info)
{
    /* System generated locals */
    integer i__1, i__2, i__3, i__4;
    real r__1, r__2;
    complex q__1, q__2, q__3;
    /* Local variables */
    integer j, k, j1, k1, jj, kk;
    complex ct;
    real ajj;
    integer j1j1;
    real akk;
    integer k1k1;
    real bjj, bkk;
    extern /* Subroutine */
    int chpr2_(char *, integer *, complex *, complex * , integer *, complex *, integer *, complex *);
    extern /* Complex */
    VOID cdotc_f2c_(complex *, integer *, complex *, integer *, complex *, integer *);
    extern logical lsame_(char *, char *);
    extern /* Subroutine */
    int chpmv_(char *, integer *, complex *, complex * , complex *, integer *, complex *, complex *, integer *), caxpy_(integer *, complex *, complex *, integer *, complex *, integer *), ctpmv_(char *, char *, char *, integer *, complex *, complex *, integer *);
    logical upper;
    extern /* Subroutine */
    int ctpsv_(char *, char *, char *, integer *, complex *, complex *, integer *), csscal_( integer *, real *, complex *, integer *), xerbla_(char *, integer *);
    /* -- LAPACK computational 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 Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Test the input parameters. */
    /* Parameter adjustments */
    --bp;
    --ap;
    /* Function Body */
    *info = 0;
    upper = lsame_(uplo, "U");
    if (*itype < 1 || *itype > 3)
    {
        *info = -1;
    }
    else if (! upper && ! lsame_(uplo, "L"))
    {
        *info = -2;
    }
    else if (*n < 0)
    {
        *info = -3;
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CHPGST", &i__1);
        return 0;
    }
    if (*itype == 1)
    {
        if (upper)
        {
            /* Compute inv(U**H)*A*inv(U) */
            /* J1 and JJ are the indices of A(1,j) and A(j,j) */
            jj = 0;
            i__1 = *n;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                j1 = jj + 1;
                jj += j;
                /* Compute the j-th column of the upper triangle of A */
                i__2 = jj;
                i__3 = jj;
                r__1 = ap[i__3].r;
                ap[i__2].r = r__1;
                ap[i__2].i = 0.f; // , expr subst
                i__2 = jj;
                bjj = bp[i__2].r;
                ctpsv_(uplo, "Conjugate transpose", "Non-unit", &j, &bp[1], & ap[j1], &c__1);
                i__2 = j - 1;
                q__1.r = -1.f;
                q__1.i = -0.f; // , expr subst
                chpmv_(uplo, &i__2, &q__1, &ap[1], &bp[j1], &c__1, &c_b1, &ap[ j1], &c__1);
                i__2 = j - 1;
                r__1 = 1.f / bjj;
                csscal_(&i__2, &r__1, &ap[j1], &c__1);
                i__2 = jj;
                i__3 = jj;
                i__4 = j - 1;
                cdotc_f2c_(&q__3, &i__4, &ap[j1], &c__1, &bp[j1], &c__1);
                q__2.r = ap[i__3].r - q__3.r;
                q__2.i = ap[i__3].i - q__3.i; // , expr subst
                q__1.r = q__2.r / bjj;
                q__1.i = q__2.i / bjj; // , expr subst
                ap[i__2].r = q__1.r;
                ap[i__2].i = q__1.i; // , expr subst
                /* L10: */
            }
        }
        else
        {
            /* Compute inv(L)*A*inv(L**H) */
            /* KK and K1K1 are the indices of A(k,k) and A(k+1,k+1) */
            kk = 1;
            i__1 = *n;
            for (k = 1;
                    k <= i__1;
                    ++k)
            {
                k1k1 = kk + *n - k + 1;
                /* Update the lower triangle of A(k:n,k:n) */
                i__2 = kk;
                akk = ap[i__2].r;
                i__2 = kk;
                bkk = bp[i__2].r;
                /* Computing 2nd power */
                r__1 = bkk;
                akk /= r__1 * r__1;
                i__2 = kk;
                ap[i__2].r = akk;
                ap[i__2].i = 0.f; // , expr subst
                if (k < *n)
                {
                    i__2 = *n - k;
                    r__1 = 1.f / bkk;
                    csscal_(&i__2, &r__1, &ap[kk + 1], &c__1);
                    r__1 = akk * -.5f;
                    ct.r = r__1;
                    ct.i = 0.f; // , expr subst
                    i__2 = *n - k;
                    caxpy_(&i__2, &ct, &bp[kk + 1], &c__1, &ap[kk + 1], &c__1) ;
                    i__2 = *n - k;
                    q__1.r = -1.f;
                    q__1.i = -0.f; // , expr subst
                    chpr2_(uplo, &i__2, &q__1, &ap[kk + 1], &c__1, &bp[kk + 1] , &c__1, &ap[k1k1]);
                    i__2 = *n - k;
                    caxpy_(&i__2, &ct, &bp[kk + 1], &c__1, &ap[kk + 1], &c__1) ;
                    i__2 = *n - k;
                    ctpsv_(uplo, "No transpose", "Non-unit", &i__2, &bp[k1k1], &ap[kk + 1], &c__1);
                }
                kk = k1k1;
                /* L20: */
            }
        }
    }
    else
    {
        if (upper)
        {
            /* Compute U*A*U**H */
            /* K1 and KK are the indices of A(1,k) and A(k,k) */
            kk = 0;
            i__1 = *n;
            for (k = 1;
                    k <= i__1;
                    ++k)
            {
                k1 = kk + 1;
                kk += k;
                /* Update the upper triangle of A(1:k,1:k) */
                i__2 = kk;
                akk = ap[i__2].r;
                i__2 = kk;
                bkk = bp[i__2].r;
                i__2 = k - 1;
                ctpmv_(uplo, "No transpose", "Non-unit", &i__2, &bp[1], &ap[ k1], &c__1);
                r__1 = akk * .5f;
                ct.r = r__1;
                ct.i = 0.f; // , expr subst
                i__2 = k - 1;
                caxpy_(&i__2, &ct, &bp[k1], &c__1, &ap[k1], &c__1);
                i__2 = k - 1;
                chpr2_(uplo, &i__2, &c_b1, &ap[k1], &c__1, &bp[k1], &c__1, & ap[1]);
                i__2 = k - 1;
                caxpy_(&i__2, &ct, &bp[k1], &c__1, &ap[k1], &c__1);
                i__2 = k - 1;
                csscal_(&i__2, &bkk, &ap[k1], &c__1);
                i__2 = kk;
                /* Computing 2nd power */
                r__2 = bkk;
                r__1 = akk * (r__2 * r__2);
                ap[i__2].r = r__1;
                ap[i__2].i = 0.f; // , expr subst
                /* L30: */
            }
        }
        else
        {
            /* Compute L**H *A*L */
            /* JJ and J1J1 are the indices of A(j,j) and A(j+1,j+1) */
            jj = 1;
            i__1 = *n;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                j1j1 = jj + *n - j + 1;
                /* Compute the j-th column of the lower triangle of A */
                i__2 = jj;
                ajj = ap[i__2].r;
                i__2 = jj;
                bjj = bp[i__2].r;
                i__2 = jj;
                r__1 = ajj * bjj;
                i__3 = *n - j;
                cdotc_f2c_(&q__2, &i__3, &ap[jj + 1], &c__1, &bp[jj + 1], &c__1);
                q__1.r = r__1 + q__2.r;
                q__1.i = q__2.i; // , expr subst
                ap[i__2].r = q__1.r;
                ap[i__2].i = q__1.i; // , expr subst
                i__2 = *n - j;
                csscal_(&i__2, &bjj, &ap[jj + 1], &c__1);
                i__2 = *n - j;
                chpmv_(uplo, &i__2, &c_b1, &ap[j1j1], &bp[jj + 1], &c__1, & c_b1, &ap[jj + 1], &c__1);
                i__2 = *n - j + 1;
                ctpmv_(uplo, "Conjugate transpose", "Non-unit", &i__2, &bp[jj] , &ap[jj], &c__1);
                jj = j1j1;
                /* L40: */
            }
        }
    }
    return 0;
    /* End of CHPGST */
}