version 1.1, 2010/01/26 15:22:45
|
version 1.11, 2012/12/14 14:22:40
|
Line 1
|
Line 1
|
|
*> \brief <b> DSTEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices</b> |
|
* |
|
* =========== DOCUMENTATION =========== |
|
* |
|
* Online html documentation available at |
|
* http://www.netlib.org/lapack/explore-html/ |
|
* |
|
*> \htmlonly |
|
*> Download DSTEV + dependencies |
|
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dstev.f"> |
|
*> [TGZ]</a> |
|
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dstev.f"> |
|
*> [ZIP]</a> |
|
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dstev.f"> |
|
*> [TXT]</a> |
|
*> \endhtmlonly |
|
* |
|
* Definition: |
|
* =========== |
|
* |
|
* SUBROUTINE DSTEV( JOBZ, N, D, E, Z, LDZ, WORK, INFO ) |
|
* |
|
* .. Scalar Arguments .. |
|
* CHARACTER JOBZ |
|
* INTEGER INFO, LDZ, N |
|
* .. |
|
* .. Array Arguments .. |
|
* DOUBLE PRECISION D( * ), E( * ), WORK( * ), Z( LDZ, * ) |
|
* .. |
|
* |
|
* |
|
*> \par Purpose: |
|
* ============= |
|
*> |
|
*> \verbatim |
|
*> |
|
*> DSTEV computes all eigenvalues and, optionally, eigenvectors of a |
|
*> real symmetric tridiagonal matrix A. |
|
*> \endverbatim |
|
* |
|
* Arguments: |
|
* ========== |
|
* |
|
*> \param[in] JOBZ |
|
*> \verbatim |
|
*> JOBZ is CHARACTER*1 |
|
*> = 'N': Compute eigenvalues only; |
|
*> = 'V': Compute eigenvalues and eigenvectors. |
|
*> \endverbatim |
|
*> |
|
*> \param[in] N |
|
*> \verbatim |
|
*> N is INTEGER |
|
*> The order of the matrix. N >= 0. |
|
*> \endverbatim |
|
*> |
|
*> \param[in,out] D |
|
*> \verbatim |
|
*> D is DOUBLE PRECISION array, dimension (N) |
|
*> On entry, the n diagonal elements of the tridiagonal matrix |
|
*> A. |
|
*> On exit, if INFO = 0, the eigenvalues in ascending order. |
|
*> \endverbatim |
|
*> |
|
*> \param[in,out] E |
|
*> \verbatim |
|
*> E is DOUBLE PRECISION array, dimension (N-1) |
|
*> On entry, the (n-1) subdiagonal elements of the tridiagonal |
|
*> matrix A, stored in elements 1 to N-1 of E. |
|
*> On exit, the contents of E are destroyed. |
|
*> \endverbatim |
|
*> |
|
*> \param[out] Z |
|
*> \verbatim |
|
*> Z is DOUBLE PRECISION 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 D(i). |
|
*> If JOBZ = 'N', then Z is not referenced. |
|
*> \endverbatim |
|
*> |
|
*> \param[in] LDZ |
|
*> \verbatim |
|
*> LDZ is INTEGER |
|
*> The leading dimension of the array Z. LDZ >= 1, and if |
|
*> JOBZ = 'V', LDZ >= max(1,N). |
|
*> \endverbatim |
|
*> |
|
*> \param[out] WORK |
|
*> \verbatim |
|
*> WORK is DOUBLE PRECISION array, dimension (max(1,2*N-2)) |
|
*> If JOBZ = 'N', WORK is not referenced. |
|
*> \endverbatim |
|
*> |
|
*> \param[out] INFO |
|
*> \verbatim |
|
*> INFO is 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 E did not converge to zero. |
|
*> \endverbatim |
|
* |
|
* Authors: |
|
* ======== |
|
* |
|
*> \author Univ. of Tennessee |
|
*> \author Univ. of California Berkeley |
|
*> \author Univ. of Colorado Denver |
|
*> \author NAG Ltd. |
|
* |
|
*> \date November 2011 |
|
* |
|
*> \ingroup doubleOTHEReigen |
|
* |
|
* ===================================================================== |
SUBROUTINE DSTEV( JOBZ, N, D, E, Z, LDZ, WORK, INFO ) |
SUBROUTINE DSTEV( JOBZ, N, D, E, Z, LDZ, WORK, INFO ) |
* |
* |
* -- LAPACK driver routine (version 3.2) -- |
* -- LAPACK driver routine (version 3.4.0) -- |
* -- LAPACK is a software package provided by Univ. of Tennessee, -- |
* -- LAPACK is a software package provided by Univ. of Tennessee, -- |
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
* November 2006 |
* November 2011 |
* |
* |
* .. Scalar Arguments .. |
* .. Scalar Arguments .. |
CHARACTER JOBZ |
CHARACTER JOBZ |
Line 13
|
Line 129
|
DOUBLE PRECISION D( * ), E( * ), WORK( * ), Z( LDZ, * ) |
DOUBLE PRECISION D( * ), E( * ), WORK( * ), Z( LDZ, * ) |
* .. |
* .. |
* |
* |
* Purpose |
|
* ======= |
|
* |
|
* DSTEV computes all eigenvalues and, optionally, eigenvectors of a |
|
* real symmetric tridiagonal matrix A. |
|
* |
|
* Arguments |
|
* ========= |
|
* |
|
* JOBZ (input) CHARACTER*1 |
|
* = 'N': Compute eigenvalues only; |
|
* = 'V': Compute eigenvalues and eigenvectors. |
|
* |
|
* N (input) INTEGER |
|
* The order of the matrix. N >= 0. |
|
* |
|
* D (input/output) DOUBLE PRECISION array, dimension (N) |
|
* On entry, the n diagonal elements of the tridiagonal matrix |
|
* A. |
|
* On exit, if INFO = 0, the eigenvalues in ascending order. |
|
* |
|
* E (input/output) DOUBLE PRECISION array, dimension (N-1) |
|
* On entry, the (n-1) subdiagonal elements of the tridiagonal |
|
* matrix A, stored in elements 1 to N-1 of E. |
|
* On exit, the contents of E are destroyed. |
|
* |
|
* Z (output) DOUBLE PRECISION 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 D(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) DOUBLE PRECISION array, dimension (max(1,2*N-2)) |
|
* If JOBZ = 'N', WORK 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, the algorithm failed to converge; i |
|
* off-diagonal elements of E did not converge to zero. |
|
* |
|
* ===================================================================== |
* ===================================================================== |
* |
* |
* .. Parameters .. |
* .. Parameters .. |