1. Manuals
  2. Tumbleweed
  3. lapack-man
  4. getc2(3)

Scroll to navigation

getc2(3) Library Functions Manual getc2(3)

NAME

getc2 - getc2: triangular factor, with complete pivoting

SYNOPSIS

Functions


subroutine CGETC2 (n, a, lda, ipiv, jpiv, info)
CGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix. subroutine DGETC2 (n, a, lda, ipiv, jpiv, info)
DGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix. subroutine SGETC2 (n, a, lda, ipiv, jpiv, info)
SGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix. subroutine ZGETC2 (n, a, lda, ipiv, jpiv, info)
ZGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Detailed Description

Function Documentation

subroutine CGETC2 (integer n, complex, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer info)

CGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

!>
!> CGETC2 computes an LU factorization, using complete pivoting, of the
!> n-by-n matrix A. The factorization has the form A = P * L * U * Q,
!> where P and Q are permutation matrices, L is lower triangular with
!> unit diagonal elements and U is upper triangular.
!>
!> This is a level 1 BLAS version of the algorithm.
!>

Parameters

N 

!>          N is INTEGER
!>          The order of the matrix A. N >= 0.
!>

A

!>          A is COMPLEX array, dimension (LDA, N)
!>          On entry, the n-by-n matrix to be factored.
!>          On exit, the factors L and U from the factorization
!>          A = P*L*U*Q; the unit diagonal elements of L are not stored.
!>          If U(k, k) appears to be less than SMIN, U(k, k) is given the
!>          value of SMIN, giving a nonsingular perturbed system.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1, N).
!>

IPIV

!>          IPIV is INTEGER array, dimension (N).
!>          The pivot indices; for 1 <= i <= N, row i of the
!>          matrix has been interchanged with row IPIV(i).
!>

JPIV

!>          JPIV is INTEGER array, dimension (N).
!>          The pivot indices; for 1 <= j <= N, column j of the
!>          matrix has been interchanged with column JPIV(j).
!>

INFO

!>          INFO is INTEGER
!>           = 0: successful exit
!>           > 0: if INFO = k, U(k, k) is likely to produce overflow if
!>                one tries to solve for x in Ax = b. So U is perturbed
!>                to avoid the overflow.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

Bo Kagstrom and Peter Poromaa, Department of Computing Science, Umea University, S-901 87 Umea, Sweden.

Definition at line 110 of file cgetc2.f.

subroutine DGETC2 (integer n, double precision, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer info)

DGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

!>
!> DGETC2 computes an LU factorization with complete pivoting of the
!> n-by-n matrix A. The factorization has the form A = P * L * U * Q,
!> where P and Q are permutation matrices, L is lower triangular with
!> unit diagonal elements and U is upper triangular.
!>
!> This is the Level 2 BLAS algorithm.
!>

Parameters

N 

!>          N is INTEGER
!>          The order of the matrix A. N >= 0.
!>

A

!>          A is DOUBLE PRECISION array, dimension (LDA, N)
!>          On entry, the n-by-n matrix A to be factored.
!>          On exit, the factors L and U from the factorization
!>          A = P*L*U*Q; the unit diagonal elements of L are not stored.
!>          If U(k, k) appears to be less than SMIN, U(k, k) is given the
!>          value of SMIN, i.e., giving a nonsingular perturbed system.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>

IPIV

!>          IPIV is INTEGER array, dimension(N).
!>          The pivot indices; for 1 <= i <= N, row i of the
!>          matrix has been interchanged with row IPIV(i).
!>

JPIV

!>          JPIV is INTEGER array, dimension(N).
!>          The pivot indices; for 1 <= j <= N, column j of the
!>          matrix has been interchanged with column JPIV(j).
!>

INFO

!>          INFO is INTEGER
!>           = 0: successful exit
!>           > 0: if INFO = k, U(k, k) is likely to produce overflow if
!>                we try to solve for x in Ax = b. So U is perturbed to
!>                avoid the overflow.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

Bo Kagstrom and Peter Poromaa, Department of Computing Science, Umea University, S-901 87 Umea, Sweden.

Definition at line 110 of file dgetc2.f.

subroutine SGETC2 (integer n, real, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer info)

SGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

!>
!> SGETC2 computes an LU factorization with complete pivoting of the
!> n-by-n matrix A. The factorization has the form A = P * L * U * Q,
!> where P and Q are permutation matrices, L is lower triangular with
!> unit diagonal elements and U is upper triangular.
!>
!> This is the Level 2 BLAS algorithm.
!>

Parameters

N 

!>          N is INTEGER
!>          The order of the matrix A. N >= 0.
!>

A

!>          A is REAL array, dimension (LDA, N)
!>          On entry, the n-by-n matrix A to be factored.
!>          On exit, the factors L and U from the factorization
!>          A = P*L*U*Q; the unit diagonal elements of L are not stored.
!>          If U(k, k) appears to be less than SMIN, U(k, k) is given the
!>          value of SMIN, i.e., giving a nonsingular perturbed system.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>

IPIV

!>          IPIV is INTEGER array, dimension(N).
!>          The pivot indices; for 1 <= i <= N, row i of the
!>          matrix has been interchanged with row IPIV(i).
!>

JPIV

!>          JPIV is INTEGER array, dimension(N).
!>          The pivot indices; for 1 <= j <= N, column j of the
!>          matrix has been interchanged with column JPIV(j).
!>

INFO

!>          INFO is INTEGER
!>           = 0: successful exit
!>           > 0: if INFO = k, U(k, k) is likely to produce overflow if
!>                we try to solve for x in Ax = b. So U is perturbed to
!>                avoid the overflow.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

Bo Kagstrom and Peter Poromaa, Department of Computing Science, Umea University, S-901 87 Umea, Sweden.

Definition at line 110 of file sgetc2.f.

subroutine ZGETC2 (integer n, complex*16, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer info)

ZGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

!>
!> ZGETC2 computes an LU factorization, using complete pivoting, of the
!> n-by-n matrix A. The factorization has the form A = P * L * U * Q,
!> where P and Q are permutation matrices, L is lower triangular with
!> unit diagonal elements and U is upper triangular.
!>
!> This is a level 1 BLAS version of the algorithm.
!>

Parameters

N 

!>          N is INTEGER
!>          The order of the matrix A. N >= 0.
!>

A

!>          A is COMPLEX*16 array, dimension (LDA, N)
!>          On entry, the n-by-n matrix to be factored.
!>          On exit, the factors L and U from the factorization
!>          A = P*L*U*Q; the unit diagonal elements of L are not stored.
!>          If U(k, k) appears to be less than SMIN, U(k, k) is given the
!>          value of SMIN, giving a nonsingular perturbed system.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1, N).
!>

IPIV

!>          IPIV is INTEGER array, dimension (N).
!>          The pivot indices; for 1 <= i <= N, row i of the
!>          matrix has been interchanged with row IPIV(i).
!>

JPIV

!>          JPIV is INTEGER array, dimension (N).
!>          The pivot indices; for 1 <= j <= N, column j of the
!>          matrix has been interchanged with column JPIV(j).
!>

INFO

!>          INFO is INTEGER
!>           = 0: successful exit
!>           > 0: if INFO = k, U(k, k) is likely to produce overflow if
!>                one tries to solve for x in Ax = b. So U is perturbed
!>                to avoid the overflow.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

Bo Kagstrom and Peter Poromaa, Department of Computing Science, Umea University, S-901 87 Umea, Sweden.

Definition at line 110 of file zgetc2.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Version 3.12.0 LAPACK