diff options
Diffstat (limited to 'digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgetf2.c')
| -rw-r--r-- | digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgetf2.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgetf2.c b/digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgetf2.c new file mode 100644 index 0000000..83bf187 --- /dev/null +++ b/digikam/imageplugins/coreplugin/sharpnesseditor/clapack/dgetf2.c @@ -0,0 +1,157 @@ +#include "blaswrap.h" +#include "f2c.h" + +/* Subroutine */ int dgetf2_(integer *m, integer *n, doublereal *a, integer * + lda, integer *ipiv, integer *info) +{ +/* -- LAPACK routine (version 3.0) -- + Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., + Courant Institute, Argonne National Lab, and Rice University + June 30, 1992 + + + Purpose + ======= + + DGETF2 computes an LU factorization of a general m-by-n matrix A + using partial pivoting with row interchanges. + + The factorization has the form + A = P * L * U + where P is a permutation matrix, L is lower triangular with unit + diagonal elements (lower trapezoidal if m > n), and U is upper + triangular (upper trapezoidal if m < n). + + This is the right-looking Level 2 BLAS version of the algorithm. + + Arguments + ========= + + M (input) INTEGER + The number of rows of the matrix A. M >= 0. + + N (input) INTEGER + The number of columns of the matrix A. N >= 0. + + A (input/output) DOUBLE PRECISION array, dimension (LDA,N) + On entry, the m by n matrix to be factored. + 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,M). + + IPIV (output) INTEGER array, dimension (min(M,N)) + The pivot indices; for 1 <= i <= min(M,N), row i of the + matrix was interchanged with row IPIV(i). + + INFO (output) INTEGER + = 0: successful exit + < 0: if INFO = -k, the k-th argument had an illegal value + > 0: if INFO = k, U(k,k) is exactly zero. The factorization + has been completed, but the factor U is exactly + singular, and division by zero will occur if it is used + to solve a system of equations. + + ===================================================================== + + + Test the input parameters. + + Parameter adjustments */ + /* Table of constant values */ + static integer c__1 = 1; + static doublereal c_b6 = -1.; + + /* System generated locals */ + integer a_dim1, a_offset, i__1, i__2, i__3; + doublereal d__1; + /* Local variables */ + extern /* Subroutine */ int dger_(integer *, integer *, doublereal *, + doublereal *, integer *, doublereal *, integer *, doublereal *, + integer *); + static integer j; + extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *, + integer *), dswap_(integer *, doublereal *, integer *, doublereal + *, integer *); + static integer jp; + extern integer idamax_(integer *, doublereal *, integer *); + extern /* Subroutine */ int xerbla_(char *, integer *); +#define a_ref(a_1,a_2) a[(a_2)*a_dim1 + a_1] + + + a_dim1 = *lda; + a_offset = 1 + a_dim1 * 1; + a -= a_offset; + --ipiv; + + /* Function Body */ + *info = 0; + if (*m < 0) { + *info = -1; + } else if (*n < 0) { + *info = -2; + } else if (*lda < max(1,*m)) { + *info = -4; + } + if (*info != 0) { + i__1 = -(*info); + xerbla_("DGETF2", &i__1); + return 0; + } + +/* Quick return if possible */ + + if (*m == 0 || *n == 0) { + return 0; + } + + i__1 = min(*m,*n); + for (j = 1; j <= i__1; ++j) { + +/* Find pivot and test for singularity. */ + + i__2 = *m - j + 1; + jp = j - 1 + idamax_(&i__2, &a_ref(j, j), &c__1); + ipiv[j] = jp; + if (a_ref(jp, j) != 0.) { + +/* Apply the interchange to columns 1:N. */ + + if (jp != j) { + dswap_(n, &a_ref(j, 1), lda, &a_ref(jp, 1), lda); + } + +/* Compute elements J+1:M of J-th column. */ + + if (j < *m) { + i__2 = *m - j; + d__1 = 1. / a_ref(j, j); + dscal_(&i__2, &d__1, &a_ref(j + 1, j), &c__1); + } + + } else if (*info == 0) { + + *info = j; + } + + if (j < min(*m,*n)) { + +/* Update trailing submatrix. */ + + i__2 = *m - j; + i__3 = *n - j; + dger_(&i__2, &i__3, &c_b6, &a_ref(j + 1, j), &c__1, &a_ref(j, j + + 1), lda, &a_ref(j + 1, j + 1), lda); + } +/* L10: */ + } + return 0; + +/* End of DGETF2 */ + +} /* dgetf2_ */ + +#undef a_ref + + |