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Diffstat (limited to 'digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgesv.c')
| -rw-r--r-- | digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgesv.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgesv.c b/digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgesv.c new file mode 100644 index 0000000..5c0dc52 --- /dev/null +++ b/digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgesv.c @@ -0,0 +1,117 @@ +#include "blaswrap.h" +#include "f2c.h" + +/* Subroutine */ int dgesv_(integer *n, integer *nrhs, doublereal *a, integer + *lda, integer *ipiv, doublereal *b, integer *ldb, integer *info) +{ +/* -- LAPACK driver routine (version 3.0) -- + Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., + Courant Institute, Argonne National Lab, and Rice University + March 31, 1993 + + + Purpose + ======= + + DGESV computes the solution to a real system of linear equations + A * X = B, + where A is an N-by-N matrix and X and B are N-by-NRHS matrices. + + The LU decomposition with partial pivoting and row interchanges is + used to factor A as + A = P * L * U, + where P is a permutation matrix, L is unit lower triangular, and U is + upper triangular. The factored form of A is then used to solve the + system of equations A * X = B. + + Arguments + ========= + + N (input) INTEGER + The number of linear equations, i.e., the order of the + matrix A. N >= 0. + + NRHS (input) INTEGER + The number of right hand sides, i.e., the number of columns + of the matrix B. NRHS >= 0. + + A (input/output) DOUBLE PRECISION array, dimension (LDA,N) + On entry, the N-by-N coefficient matrix A. + On exit, the factors L and U from the factorization + A = P*L*U; the unit diagonal elements of L are not stored. + + LDA (input) INTEGER + The leading dimension of the array A. LDA >= max(1,N). + + IPIV (output) INTEGER array, dimension (N) + The pivot indices that define the permutation matrix P; + row i of the matrix was interchanged with row IPIV(i). + + B (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS) + On entry, the N-by-NRHS matrix of right hand side matrix B. + On exit, if INFO = 0, the N-by-NRHS solution matrix X. + + LDB (input) INTEGER + The leading dimension of the array B. LDB >= max(1,N). + + INFO (output) INTEGER + = 0: successful exit + < 0: if INFO = -i, the i-th argument had an illegal value + > 0: if INFO = i, U(i,i) is exactly zero. The factorization + has been completed, but the factor U is exactly + singular, so the solution could not be computed. + + ===================================================================== + + + Test the input parameters. + + Parameter adjustments */ + /* System generated locals */ + integer a_dim1, a_offset, b_dim1, b_offset, i__1; + /* Local variables */ + extern /* Subroutine */ int dgetrf_(integer *, integer *, doublereal *, + integer *, integer *, integer *), xerbla_(char *, integer *), dgetrs_(char *, integer *, integer *, doublereal *, + integer *, integer *, doublereal *, integer *, integer *); + + a_dim1 = *lda; + a_offset = 1 + a_dim1 * 1; + a -= a_offset; + --ipiv; + b_dim1 = *ldb; + b_offset = 1 + b_dim1 * 1; + b -= b_offset; + + /* Function Body */ + *info = 0; + if (*n < 0) { + *info = -1; + } else if (*nrhs < 0) { + *info = -2; + } else if (*lda < max(1,*n)) { + *info = -4; + } else if (*ldb < max(1,*n)) { + *info = -7; + } + if (*info != 0) { + i__1 = -(*info); + xerbla_("DGESV ", &i__1); + return 0; + } + +/* Compute the LU factorization of A. */ + + dgetrf_(n, n, &a[a_offset], lda, &ipiv[1], info); + if (*info == 0) { + +/* Solve the system A*X = B, overwriting B with X. */ + + dgetrs_("No transpose", n, nrhs, &a[a_offset], lda, &ipiv[1], &b[ + b_offset], ldb, info); + } + return 0; + +/* End of DGESV */ + +} /* dgesv_ */ + |