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version 1.11, 2012/12/14 12:30:20
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*> \brief \b DGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix. |
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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 DGETC2 + dependencies |
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*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dgetc2.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/dgetc2.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/dgetc2.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 DGETC2( N, A, LDA, IPIV, JPIV, INFO ) |
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* |
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* .. Scalar Arguments .. |
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* INTEGER INFO, LDA, N |
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* .. |
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* .. Array Arguments .. |
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* INTEGER IPIV( * ), JPIV( * ) |
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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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*> DGETC2 computes an LU factorization with complete pivoting of the |
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*> n-by-n matrix A. The factorization has the form A = P * L * U * Q, |
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*> where P and Q are permutation matrices, L is lower triangular with |
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*> unit diagonal elements and U is upper triangular. |
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*> |
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*> This is the Level 2 BLAS 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] 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 n-by-n matrix A to be factored. |
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*> On exit, the factors L and U from the factorization |
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*> A = P*L*U*Q; the unit diagonal elements of L are not stored. |
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*> If U(k, k) appears to be less than SMIN, U(k, k) is given the |
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*> value of SMIN, i.e., giving a nonsingular perturbed system. |
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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] IPIV |
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*> \verbatim |
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*> IPIV is INTEGER array, dimension(N). |
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*> The pivot indices; for 1 <= i <= N, row i of the |
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*> matrix has been interchanged with row IPIV(i). |
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*> \endverbatim |
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*> |
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*> \param[out] JPIV |
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*> \verbatim |
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*> JPIV is INTEGER array, dimension(N). |
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*> The pivot indices; for 1 <= j <= N, column j of the |
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*> matrix has been interchanged with column JPIV(j). |
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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, U(k, k) is likely to produce owerflow if |
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*> we try to solve for x in Ax = b. So U is perturbed to |
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*> avoid the overflow. |
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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 doubleGEauxiliary |
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* |
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*> \par Contributors: |
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* ================== |
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*> |
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*> Bo Kagstrom and Peter Poromaa, Department of Computing Science, |
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*> Umea University, S-901 87 Umea, Sweden. |
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* |
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* ===================================================================== |
SUBROUTINE DGETC2( N, A, LDA, IPIV, JPIV, INFO ) |
SUBROUTINE DGETC2( N, A, LDA, IPIV, JPIV, INFO ) |
* |
* |
* -- LAPACK auxiliary routine (version 3.2) -- |
* -- LAPACK auxiliary 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 .. |
INTEGER INFO, LDA, N |
INTEGER INFO, LDA, N |
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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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* DGETC2 computes an LU factorization with complete pivoting of the |
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* n-by-n matrix A. The factorization has the form A = P * L * U * Q, |
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* where P and Q are permutation matrices, L is lower triangular with |
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* unit diagonal elements and U is upper triangular. |
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* |
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* This is the Level 2 BLAS algorithm. |
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* |
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* Arguments |
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* ========= |
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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 n-by-n matrix A to be factored. |
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* On exit, the factors L and U from the factorization |
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* A = P*L*U*Q; the unit diagonal elements of L are not stored. |
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* If U(k, k) appears to be less than SMIN, U(k, k) is given the |
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* value of SMIN, i.e., giving a nonsingular perturbed system. |
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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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* IPIV (output) INTEGER array, dimension(N). |
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* The pivot indices; for 1 <= i <= N, row i of the |
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* matrix has been interchanged with row IPIV(i). |
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* |
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* JPIV (output) INTEGER array, dimension(N). |
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* The pivot indices; for 1 <= j <= N, column j of the |
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* matrix has been interchanged with column JPIV(j). |
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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, U(k, k) is likely to produce owerflow if |
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* we try to solve for x in Ax = b. So U is perturbed to |
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* avoid the overflow. |
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* |
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* Further Details |
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* =============== |
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* |
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* Based on contributions by |
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* Bo Kagstrom and Peter Poromaa, Department of Computing Science, |
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* Umea University, S-901 87 Umea, Sweden. |
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* |
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* ===================================================================== |
* ===================================================================== |
* |
* |
* .. Parameters .. |
* .. Parameters .. |