int sspgv_(int *itype, char *jobz, char *uplo, int * n, float *ap, float *bp, float *w, float *z__, int *ldz, float *work, int *info) { /* System generated locals */ int z_dim1, z_offset, i__1; /* Local variables */ int j, neig; extern int lsame_(char *, char *); char trans[1]; int upper; extern int sspev_(char *, char *, int *, float *, float *, float *, int *, float *, int *); int wantz; extern int stpmv_(char *, char *, char *, int *, float *, float *, int *), stpsv_(char *, char *, char *, int *, float *, float *, int *), xerbla_(char *, int *), spptrf_(char *, int *, float *, int *), sspgst_(int *, char *, int *, float *, float *, int *); /* -- LAPACK driver routine (version 3.2) -- */ /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ /* November 2006 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* SSPGV computes all the eigenvalues and, optionally, the eigenvectors */ /* of a float generalized symmetric-definite eigenproblem, of the form */ /* A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x. */ /* Here A and B are assumed to be symmetric, stored in packed format, */ /* and B is also positive definite. */ /* Arguments */ /* ========= */ /* ITYPE (input) INTEGER */ /* Specifies the problem type to be solved: */ /* = 1: A*x = (lambda)*B*x */ /* = 2: A*B*x = (lambda)*x */ /* = 3: B*A*x = (lambda)*x */ /* 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. */ /* AP (input/output) REAL array, dimension */ /* (N*(N+1)/2) */ /* On entry, the upper or lower triangle of the symmetric 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, the contents of AP are destroyed. */ /* BP (input/output) REAL array, dimension (N*(N+1)/2) */ /* On entry, the upper or lower triangle of the symmetric matrix */ /* B, packed columnwise in a linear array. The j-th column of B */ /* is stored in the array BP as follows: */ /* if UPLO = 'U', BP(i + (j-1)*j/2) = B(i,j) for 1<=i<=j; */ /* if UPLO = 'L', BP(i + (j-1)*(2*n-j)/2) = B(i,j) for j<=i<=n. */ /* On exit, the triangular factor U or L from the Cholesky */ /* factorization B = U**T*U or B = L*L**T, in the same storage */ /* format as B. */ /* W (output) REAL array, dimension (N) */ /* If INFO = 0, the eigenvalues in ascending order. */ /* Z (output) REAL array, dimension (LDZ, N) */ /* If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of */ /* eigenvectors. The eigenvectors are normalized as follows: */ /* if ITYPE = 1 or 2, Z**T*B*Z = I; */ /* if ITYPE = 3, Z**T*inv(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 >= MAX(1,N). */ /* WORK (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: SPPTRF or SSPEV returned an error code: */ /* <= N: if INFO = i, SSPEV 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 the leading */ /* minor of order i of B is not positive definite. */ /* The factorization of B could not be completed and */ /* no eigenvalues or eigenvectors were computed. */ /* ===================================================================== */ /* .. Local Scalars .. */ /* .. */ /* .. External Functions .. */ /* .. */ /* .. External Subroutines .. */ /* .. */ /* .. Executable Statements .. */ /* Test the input parameters. */ /* Parameter adjustments */ --ap; --bp; --w; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; --work; /* Function Body */ wantz = lsame_(jobz, "V"); upper = lsame_(uplo, "U"); *info = 0; if (*itype < 1 || *itype > 3) { *info = -1; } else if (! (wantz || lsame_(jobz, "N"))) { *info = -2; } else if (! (upper || lsame_(uplo, "L"))) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*ldz < 1 || wantz && *ldz < *n) { *info = -9; } if (*info != 0) { i__1 = -(*info); xerbla_("SSPGV ", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } /* Form a Cholesky factorization of B. */ spptrf_(uplo, n, &bp[1], info); if (*info != 0) { *info = *n + *info; return 0; } /* Transform problem to standard eigenvalue problem and solve. */ sspgst_(itype, uplo, n, &ap[1], &bp[1], info); sspev_(jobz, uplo, n, &ap[1], &w[1], &z__[z_offset], ldz, &work[1], info); if (wantz) { /* Backtransform eigenvectors to the original problem. */ neig = *n; if (*info > 0) { neig = *info - 1; } if (*itype == 1 || *itype == 2) { /* For A*x=(lambda)*B*x and A*B*x=(lambda)*x; */ /* backtransform eigenvectors: x = inv(L)'*y or inv(U)*y */ if (upper) { *(unsigned char *)trans = 'N'; } else { *(unsigned char *)trans = 'T'; } i__1 = neig; for (j = 1; j <= i__1; ++j) { stpsv_(uplo, trans, "Non-unit", n, &bp[1], &z__[j * z_dim1 + 1], &c__1); /* L10: */ } } else if (*itype == 3) { /* For B*A*x=(lambda)*x; */ /* backtransform eigenvectors: x = L*y or U'*y */ if (upper) { *(unsigned char *)trans = 'T'; } else { *(unsigned char *)trans = 'N'; } i__1 = neig; for (j = 1; j <= i__1; ++j) { stpmv_(uplo, trans, "Non-unit", n, &bp[1], &z__[j * z_dim1 + 1], &c__1); /* L20: */ } } } return 0; /* End of SSPGV */ } /* sspgv_ */
/* Subroutine */ int sspgv_(integer *itype, char *jobz, char *uplo, integer * n, real *ap, real *bp, real *w, real *z__, integer *ldz, real *work, 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 September 30, 1994 Purpose ======= SSPGV computes all the eigenvalues and, optionally, the eigenvectors of a real generalized symmetric-definite eigenproblem, of the form A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x. Here A and B are assumed to be symmetric, stored in packed format, and B is also positive definite. Arguments ========= ITYPE (input) INTEGER Specifies the problem type to be solved: = 1: A*x = (lambda)*B*x = 2: A*B*x = (lambda)*x = 3: B*A*x = (lambda)*x 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. AP (input/output) REAL array, dimension (N*(N+1)/2) On entry, the upper or lower triangle of the symmetric 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, the contents of AP are destroyed. BP (input/output) REAL array, dimension (N*(N+1)/2) On entry, the upper or lower triangle of the symmetric matrix B, packed columnwise in a linear array. The j-th column of B is stored in the array BP as follows: if UPLO = 'U', BP(i + (j-1)*j/2) = B(i,j) for 1<=i<=j; if UPLO = 'L', BP(i + (j-1)*(2*n-j)/2) = B(i,j) for j<=i<=n. On exit, the triangular factor U or L from the Cholesky factorization B = U**T*U or B = L*L**T, in the same storage format as B. W (output) REAL array, dimension (N) If INFO = 0, the eigenvalues in ascending order. Z (output) REAL array, dimension (LDZ, N) If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of eigenvectors. The eigenvectors are normalized as follows: if ITYPE = 1 or 2, Z**T*B*Z = I; if ITYPE = 3, Z**T*inv(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 >= max(1,N). WORK (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: SPPTRF or SSPEV returned an error code: <= N: if INFO = i, SSPEV 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 the leading minor of order i of 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 */ /* Table of constant values */ static integer c__1 = 1; /* System generated locals */ integer z_dim1, z_offset, i__1; /* Local variables */ static integer neig, j; extern logical lsame_(char *, char *); static char trans[1]; static logical upper; extern /* Subroutine */ int sspev_(char *, char *, integer *, real *, real *, real *, integer *, real *, integer *); static logical wantz; extern /* Subroutine */ int stpmv_(char *, char *, char *, integer *, real *, real *, integer *), stpsv_(char *, char *, char *, integer *, real *, real *, integer *), xerbla_(char *, integer *), spptrf_(char *, integer *, real *, integer *), sspgst_(integer *, char *, integer *, real *, real *, integer *); #define z___ref(a_1,a_2) z__[(a_2)*z_dim1 + a_1] --ap; --bp; --w; z_dim1 = *ldz; z_offset = 1 + z_dim1 * 1; z__ -= z_offset; --work; /* Function Body */ wantz = lsame_(jobz, "V"); upper = lsame_(uplo, "U"); *info = 0; if (*itype < 0 || *itype > 3) { *info = -1; } else if (! (wantz || lsame_(jobz, "N"))) { *info = -2; } else if (! (upper || lsame_(uplo, "L"))) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*ldz < 1 || wantz && *ldz < *n) { *info = -9; } if (*info != 0) { i__1 = -(*info); xerbla_("SSPGV ", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } /* Form a Cholesky factorization of B. */ spptrf_(uplo, n, &bp[1], info); if (*info != 0) { *info = *n + *info; return 0; } /* Transform problem to standard eigenvalue problem and solve. */ sspgst_(itype, uplo, n, &ap[1], &bp[1], info); sspev_(jobz, uplo, n, &ap[1], &w[1], &z__[z_offset], ldz, &work[1], info); if (wantz) { /* Backtransform eigenvectors to the original problem. */ neig = *n; if (*info > 0) { neig = *info - 1; } if (*itype == 1 || *itype == 2) { /* For A*x=(lambda)*B*x and A*B*x=(lambda)*x; backtransform eigenvectors: x = inv(L)'*y or inv(U)*y */ if (upper) { *(unsigned char *)trans = 'N'; } else { *(unsigned char *)trans = 'T'; } i__1 = neig; for (j = 1; j <= i__1; ++j) { stpsv_(uplo, trans, "Non-unit", n, &bp[1], &z___ref(1, j), & c__1); /* L10: */ } } else if (*itype == 3) { /* For B*A*x=(lambda)*x; backtransform eigenvectors: x = L*y or U'*y */ if (upper) { *(unsigned char *)trans = 'T'; } else { *(unsigned char *)trans = 'N'; } i__1 = neig; for (j = 1; j <= i__1; ++j) { stpmv_(uplo, trans, "Non-unit", n, &bp[1], &z___ref(1, j), & c__1); /* L20: */ } } } return 0; /* End of SSPGV */ } /* sspgv_ */