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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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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.
Download DGETC2 + dependencies [TGZ] [ZIP] [TXT]
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.
[in] | N | N is INTEGER The order of the matrix A. N >= 0. |
[in,out] | 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. |
[in] | LDA | LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). |
[out] | 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). |
[out] | 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). |
[out] | INFO | INFO is INTEGER = 0: successful exit > 0: if INFO = k, U(k, k) is likely to produce owerflow if we try to solve for x in Ax = b. So U is perturbed to avoid the overflow. |
Definition at line 113 of file dgetc2.f.