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version 1.12, 2012/12/14 14:22:42
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*> \brief \b DTRTI2 computes the inverse of a triangular matrix (unblocked algorithm). |
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* |
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* =========== DOCUMENTATION =========== |
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* |
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* Online html documentation available at |
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* http://www.netlib.org/lapack/explore-html/ |
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* |
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*> \htmlonly |
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*> Download DTRTI2 + dependencies |
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*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dtrti2.f"> |
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*> [TGZ]</a> |
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*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dtrti2.f"> |
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*> [ZIP]</a> |
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*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dtrti2.f"> |
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*> [TXT]</a> |
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*> \endhtmlonly |
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* |
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* Definition: |
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* =========== |
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* |
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* SUBROUTINE DTRTI2( UPLO, DIAG, N, A, LDA, INFO ) |
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* |
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* .. Scalar Arguments .. |
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* CHARACTER DIAG, UPLO |
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* INTEGER INFO, LDA, N |
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* .. |
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* .. Array Arguments .. |
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* DOUBLE PRECISION A( LDA, * ) |
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* .. |
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* |
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* |
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*> \par Purpose: |
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* ============= |
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*> |
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*> \verbatim |
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*> |
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*> DTRTI2 computes the inverse of a real upper or lower triangular |
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*> matrix. |
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*> |
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*> This is the Level 2 BLAS version of the algorithm. |
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*> \endverbatim |
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* |
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* Arguments: |
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* ========== |
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* |
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*> \param[in] UPLO |
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*> \verbatim |
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*> UPLO is CHARACTER*1 |
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*> Specifies whether the matrix A is upper or lower triangular. |
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*> = 'U': Upper triangular |
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*> = 'L': Lower triangular |
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*> \endverbatim |
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*> |
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*> \param[in] DIAG |
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*> \verbatim |
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*> DIAG is CHARACTER*1 |
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*> Specifies whether or not the matrix A is unit triangular. |
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*> = 'N': Non-unit triangular |
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*> = 'U': Unit triangular |
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*> \endverbatim |
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*> |
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*> \param[in] N |
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*> \verbatim |
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*> N is INTEGER |
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*> The order of the matrix A. N >= 0. |
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*> \endverbatim |
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*> |
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*> \param[in,out] A |
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*> \verbatim |
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*> A is DOUBLE PRECISION array, dimension (LDA,N) |
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*> On entry, the triangular matrix A. If UPLO = 'U', the |
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*> leading n by n upper triangular part of the array A contains |
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*> the upper triangular matrix, and the strictly lower |
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*> triangular part of A is not referenced. If UPLO = 'L', the |
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*> leading n by n lower triangular part of the array A contains |
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*> the lower triangular matrix, and the strictly upper |
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*> triangular part of A is not referenced. If DIAG = 'U', the |
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*> diagonal elements of A are also not referenced and are |
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*> assumed to be 1. |
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*> |
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*> On exit, the (triangular) inverse of the original matrix, in |
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*> the same storage format. |
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*> \endverbatim |
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*> |
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*> \param[in] LDA |
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*> \verbatim |
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*> LDA is INTEGER |
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*> The leading dimension of the array A. LDA >= max(1,N). |
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*> \endverbatim |
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*> |
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*> \param[out] INFO |
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*> \verbatim |
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*> INFO is INTEGER |
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*> = 0: successful exit |
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*> < 0: if INFO = -k, the k-th argument had an illegal value |
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*> \endverbatim |
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* |
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* Authors: |
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* ======== |
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* |
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*> \author Univ. of Tennessee |
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*> \author Univ. of California Berkeley |
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*> \author Univ. of Colorado Denver |
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*> \author NAG Ltd. |
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* |
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*> \date September 2012 |
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* |
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*> \ingroup doubleOTHERcomputational |
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* |
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* ===================================================================== |
SUBROUTINE DTRTI2( UPLO, DIAG, N, A, LDA, INFO ) |
SUBROUTINE DTRTI2( UPLO, DIAG, N, A, LDA, INFO ) |
* |
* |
* -- LAPACK routine (version 3.2) -- |
* -- LAPACK computational routine (version 3.4.2) -- |
* -- 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 |
* September 2012 |
* |
* |
* .. Scalar Arguments .. |
* .. Scalar Arguments .. |
CHARACTER DIAG, UPLO |
CHARACTER DIAG, UPLO |
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DOUBLE PRECISION A( LDA, * ) |
DOUBLE PRECISION A( LDA, * ) |
* .. |
* .. |
* |
* |
* Purpose |
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* ======= |
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* |
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* DTRTI2 computes the inverse of a real upper or lower triangular |
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* matrix. |
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* |
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* This is the Level 2 BLAS version of the algorithm. |
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* |
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* Arguments |
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* ========= |
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* |
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* UPLO (input) CHARACTER*1 |
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* Specifies whether the matrix A is upper or lower triangular. |
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* = 'U': Upper triangular |
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* = 'L': Lower triangular |
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* |
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* DIAG (input) CHARACTER*1 |
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* Specifies whether or not the matrix A is unit triangular. |
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* = 'N': Non-unit triangular |
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* = 'U': Unit triangular |
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* |
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* N (input) INTEGER |
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* The order of the matrix A. N >= 0. |
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* |
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* A (input/output) DOUBLE PRECISION array, dimension (LDA,N) |
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* On entry, the triangular matrix A. If UPLO = 'U', the |
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* leading n by n upper triangular part of the array A contains |
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* the upper triangular matrix, and the strictly lower |
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* triangular part of A is not referenced. If UPLO = 'L', the |
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* leading n by n lower triangular part of the array A contains |
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* the lower triangular matrix, and the strictly upper |
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* triangular part of A is not referenced. If DIAG = 'U', the |
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* diagonal elements of A are also not referenced and are |
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* assumed to be 1. |
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* |
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* On exit, the (triangular) inverse of the original matrix, in |
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* the same storage format. |
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* |
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* LDA (input) INTEGER |
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* The leading dimension of the array A. LDA >= max(1,N). |
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* |
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* INFO (output) INTEGER |
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* = 0: successful exit |
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* < 0: if INFO = -k, the k-th argument had an illegal value |
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* |
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* ===================================================================== |
* ===================================================================== |
* |
* |
* .. Parameters .. |
* .. Parameters .. |