table of contents
| getc2(3) | LAPACK | 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 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 California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Contributors:
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 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 California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Contributors:
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 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 California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Contributors:
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 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 California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Contributors:
Author¶
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| Wed Feb 7 2024 11:30:40 | Version 3.12.0 |