X-Git-Url: http://git.maemo.org/git/?p=opencv;a=blobdiff_plain;f=3rdparty%2Flapack%2Fspotf2.c;fp=3rdparty%2Flapack%2Fspotf2.c;h=a21af39560bea08b588d626085c07d76fa336f74;hp=0000000000000000000000000000000000000000;hb=e4c14cdbdf2fe805e79cd96ded236f57e7b89060;hpb=454138ff8a20f6edb9b65a910101403d8b520643 diff --git a/3rdparty/lapack/spotf2.c b/3rdparty/lapack/spotf2.c new file mode 100644 index 0000000..a21af39 --- /dev/null +++ b/3rdparty/lapack/spotf2.c @@ -0,0 +1,207 @@ +#include "clapack.h" + +/* Table of constant values */ + +static integer c__1 = 1; +static real c_b10 = -1.f; +static real c_b12 = 1.f; + +/* Subroutine */ int spotf2_(char *uplo, integer *n, real *a, integer *lda, + integer *info) +{ + /* System generated locals */ + integer a_dim1, a_offset, i__1, i__2, i__3; + real r__1; + + /* Builtin functions */ + double sqrt(doublereal); + + /* Local variables */ + integer j; + real ajj; + extern doublereal sdot_(integer *, real *, integer *, real *, integer *); + extern logical lsame_(char *, char *); + extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *), + sgemv_(char *, integer *, integer *, real *, real *, integer *, + real *, integer *, real *, real *, integer *); + logical upper; + extern /* Subroutine */ int xerbla_(char *, integer *); + + +/* -- LAPACK routine (version 3.1) -- */ +/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ +/* November 2006 */ + +/* .. Scalar Arguments .. */ +/* .. */ +/* .. Array Arguments .. */ +/* .. */ + +/* Purpose */ +/* ======= */ + +/* SPOTF2 computes the Cholesky factorization of a real symmetric */ +/* positive definite matrix A. */ + +/* The factorization has the form */ +/* A = U' * U , if UPLO = 'U', or */ +/* A = L * L', if UPLO = 'L', */ +/* where U is an upper triangular matrix and L is lower triangular. */ + +/* This is the unblocked version of the algorithm, calling Level 2 BLAS. */ + +/* Arguments */ +/* ========= */ + +/* UPLO (input) CHARACTER*1 */ +/* Specifies whether the upper or lower triangular part of the */ +/* symmetric matrix A is stored. */ +/* = 'U': Upper triangular */ +/* = 'L': Lower triangular */ + +/* N (input) INTEGER */ +/* The order of the matrix A. N >= 0. */ + +/* A (input/output) REAL array, dimension (LDA,N) */ +/* On entry, the symmetric matrix A. If UPLO = 'U', the leading */ +/* n by n upper triangular part of A contains the upper */ +/* triangular part of the matrix A, and the strictly lower */ +/* triangular part of A is not referenced. If UPLO = 'L', the */ +/* leading n by n lower triangular part of A contains the lower */ +/* triangular part of the matrix A, and the strictly upper */ +/* triangular part of A is not referenced. */ + +/* On exit, if INFO = 0, the factor U or L from the Cholesky */ +/* factorization A = U'*U or A = L*L'. */ + +/* LDA (input) INTEGER */ +/* The leading dimension of the array A. LDA >= max(1,N). */ + +/* INFO (output) INTEGER */ +/* = 0: successful exit */ +/* < 0: if INFO = -k, the k-th argument had an illegal value */ +/* > 0: if INFO = k, the leading minor of order k is not */ +/* positive definite, and the factorization could not be */ +/* completed. */ + +/* ===================================================================== */ + +/* .. Parameters .. */ +/* .. */ +/* .. Local Scalars .. */ +/* .. */ +/* .. External Functions .. */ +/* .. */ +/* .. External Subroutines .. */ +/* .. */ +/* .. Intrinsic Functions .. */ +/* .. */ +/* .. Executable Statements .. */ + +/* Test the input parameters. */ + + /* Parameter adjustments */ + a_dim1 = *lda; + a_offset = 1 + a_dim1; + a -= a_offset; + + /* Function Body */ + *info = 0; + upper = lsame_(uplo, "U"); + if (! upper && ! lsame_(uplo, "L")) { + *info = -1; + } else if (*n < 0) { + *info = -2; + } else if (*lda < max(1,*n)) { + *info = -4; + } + if (*info != 0) { + i__1 = -(*info); + xerbla_("SPOTF2", &i__1); + return 0; + } + +/* Quick return if possible */ + + if (*n == 0) { + return 0; + } + + if (upper) { + +/* Compute the Cholesky factorization A = U'*U. */ + + i__1 = *n; + for (j = 1; j <= i__1; ++j) { + +/* Compute U(J,J) and test for non-positive-definiteness. */ + + i__2 = j - 1; + ajj = a[j + j * a_dim1] - sdot_(&i__2, &a[j * a_dim1 + 1], &c__1, + &a[j * a_dim1 + 1], &c__1); + if (ajj <= 0.f) { + a[j + j * a_dim1] = ajj; + goto L30; + } + ajj = sqrt(ajj); + a[j + j * a_dim1] = ajj; + +/* Compute elements J+1:N of row J. */ + + if (j < *n) { + i__2 = j - 1; + i__3 = *n - j; + sgemv_("Transpose", &i__2, &i__3, &c_b10, &a[(j + 1) * a_dim1 + + 1], lda, &a[j * a_dim1 + 1], &c__1, &c_b12, &a[j + ( + j + 1) * a_dim1], lda); + i__2 = *n - j; + r__1 = 1.f / ajj; + sscal_(&i__2, &r__1, &a[j + (j + 1) * a_dim1], lda); + } +/* L10: */ + } + } else { + +/* Compute the Cholesky factorization A = L*L'. */ + + i__1 = *n; + for (j = 1; j <= i__1; ++j) { + +/* Compute L(J,J) and test for non-positive-definiteness. */ + + i__2 = j - 1; + ajj = a[j + j * a_dim1] - sdot_(&i__2, &a[j + a_dim1], lda, &a[j + + a_dim1], lda); + if (ajj <= 0.f) { + a[j + j * a_dim1] = ajj; + goto L30; + } + ajj = sqrt(ajj); + a[j + j * a_dim1] = ajj; + +/* Compute elements J+1:N of column J. */ + + if (j < *n) { + i__2 = *n - j; + i__3 = j - 1; + sgemv_("No transpose", &i__2, &i__3, &c_b10, &a[j + 1 + + a_dim1], lda, &a[j + a_dim1], lda, &c_b12, &a[j + 1 + + j * a_dim1], &c__1); + i__2 = *n - j; + r__1 = 1.f / ajj; + sscal_(&i__2, &r__1, &a[j + 1 + j * a_dim1], &c__1); + } +/* L20: */ + } + } + goto L40; + +L30: + *info = j; + +L40: + return 0; + +/* End of SPOTF2 */ + +} /* spotf2_ */