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authorshmel1k <shmel1k@ydb.tech>2022-09-02 12:44:59 +0300
committershmel1k <shmel1k@ydb.tech>2022-09-02 12:44:59 +0300
commit90d450f74722da7859d6f510a869f6c6908fd12f (patch)
tree538c718dedc76cdfe37ad6d01ff250dd930d9278 /contrib/libs/clapack/dgtsv.c
parent01f64c1ecd0d4ffa9e3a74478335f1745f26cc75 (diff)
downloadydb-90d450f74722da7859d6f510a869f6c6908fd12f.tar.gz
[] add metering mode to CLI
Diffstat (limited to 'contrib/libs/clapack/dgtsv.c')
-rw-r--r--contrib/libs/clapack/dgtsv.c315
1 files changed, 315 insertions, 0 deletions
diff --git a/contrib/libs/clapack/dgtsv.c b/contrib/libs/clapack/dgtsv.c
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+/* dgtsv.f -- translated by f2c (version 20061008).
+ You must link the resulting object file with libf2c:
+ on Microsoft Windows system, link with libf2c.lib;
+ on Linux or Unix systems, link with .../path/to/libf2c.a -lm
+ or, if you install libf2c.a in a standard place, with -lf2c -lm
+ -- in that order, at the end of the command line, as in
+ cc *.o -lf2c -lm
+ Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
+
+ http://www.netlib.org/f2c/libf2c.zip
+*/
+
+#include "f2c.h"
+#include "blaswrap.h"
+
+/* Subroutine */ int dgtsv_(integer *n, integer *nrhs, doublereal *dl,
+ doublereal *d__, doublereal *du, doublereal *b, integer *ldb, integer
+ *info)
+{
+ /* System generated locals */
+ integer b_dim1, b_offset, i__1, i__2;
+ doublereal d__1, d__2;
+
+ /* Local variables */
+ integer i__, j;
+ doublereal fact, temp;
+ extern /* Subroutine */ int xerbla_(char *, integer *);
+
+
+/* -- LAPACK routine (version 3.2) -- */
+/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/* November 2006 */
+
+/* .. Scalar Arguments .. */
+/* .. */
+/* .. Array Arguments .. */
+/* .. */
+
+/* Purpose */
+/* ======= */
+
+/* DGTSV solves the equation */
+
+/* A*X = B, */
+
+/* where A is an n by n tridiagonal matrix, by Gaussian elimination with */
+/* partial pivoting. */
+
+/* Note that the equation A'*X = B may be solved by interchanging the */
+/* order of the arguments DU and DL. */
+
+/* Arguments */
+/* ========= */
+
+/* N (input) INTEGER */
+/* 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. */
+
+/* DL (input/output) DOUBLE PRECISION array, dimension (N-1) */
+/* On entry, DL must contain the (n-1) sub-diagonal elements of */
+/* A. */
+
+/* On exit, DL is overwritten by the (n-2) elements of the */
+/* second super-diagonal of the upper triangular matrix U from */
+/* the LU factorization of A, in DL(1), ..., DL(n-2). */
+
+/* D (input/output) DOUBLE PRECISION array, dimension (N) */
+/* On entry, D must contain the diagonal elements of A. */
+
+/* On exit, D is overwritten by the n diagonal elements of U. */
+
+/* DU (input/output) DOUBLE PRECISION array, dimension (N-1) */
+/* On entry, DU must contain the (n-1) super-diagonal elements */
+/* of A. */
+
+/* On exit, DU is overwritten by the (n-1) elements of the first */
+/* super-diagonal of U. */
+
+/* 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, and the solution */
+/* has not been computed. The factorization has not been */
+/* completed unless i = N. */
+
+/* ===================================================================== */
+
+/* .. Parameters .. */
+/* .. */
+/* .. Local Scalars .. */
+/* .. */
+/* .. Intrinsic Functions .. */
+/* .. */
+/* .. External Subroutines .. */
+/* .. */
+/* .. Executable Statements .. */
+
+ /* Parameter adjustments */
+ --dl;
+ --d__;
+ --du;
+ b_dim1 = *ldb;
+ b_offset = 1 + b_dim1;
+ b -= b_offset;
+
+ /* Function Body */
+ *info = 0;
+ if (*n < 0) {
+ *info = -1;
+ } else if (*nrhs < 0) {
+ *info = -2;
+ } else if (*ldb < max(1,*n)) {
+ *info = -7;
+ }
+ if (*info != 0) {
+ i__1 = -(*info);
+ xerbla_("DGTSV ", &i__1);
+ return 0;
+ }
+
+ if (*n == 0) {
+ return 0;
+ }
+
+ if (*nrhs == 1) {
+ i__1 = *n - 2;
+ for (i__ = 1; i__ <= i__1; ++i__) {
+ if ((d__1 = d__[i__], abs(d__1)) >= (d__2 = dl[i__], abs(d__2))) {
+
+/* No row interchange required */
+
+ if (d__[i__] != 0.) {
+ fact = dl[i__] / d__[i__];
+ d__[i__ + 1] -= fact * du[i__];
+ b[i__ + 1 + b_dim1] -= fact * b[i__ + b_dim1];
+ } else {
+ *info = i__;
+ return 0;
+ }
+ dl[i__] = 0.;
+ } else {
+
+/* Interchange rows I and I+1 */
+
+ fact = d__[i__] / dl[i__];
+ d__[i__] = dl[i__];
+ temp = d__[i__ + 1];
+ d__[i__ + 1] = du[i__] - fact * temp;
+ dl[i__] = du[i__ + 1];
+ du[i__ + 1] = -fact * dl[i__];
+ du[i__] = temp;
+ temp = b[i__ + b_dim1];
+ b[i__ + b_dim1] = b[i__ + 1 + b_dim1];
+ b[i__ + 1 + b_dim1] = temp - fact * b[i__ + 1 + b_dim1];
+ }
+/* L10: */
+ }
+ if (*n > 1) {
+ i__ = *n - 1;
+ if ((d__1 = d__[i__], abs(d__1)) >= (d__2 = dl[i__], abs(d__2))) {
+ if (d__[i__] != 0.) {
+ fact = dl[i__] / d__[i__];
+ d__[i__ + 1] -= fact * du[i__];
+ b[i__ + 1 + b_dim1] -= fact * b[i__ + b_dim1];
+ } else {
+ *info = i__;
+ return 0;
+ }
+ } else {
+ fact = d__[i__] / dl[i__];
+ d__[i__] = dl[i__];
+ temp = d__[i__ + 1];
+ d__[i__ + 1] = du[i__] - fact * temp;
+ du[i__] = temp;
+ temp = b[i__ + b_dim1];
+ b[i__ + b_dim1] = b[i__ + 1 + b_dim1];
+ b[i__ + 1 + b_dim1] = temp - fact * b[i__ + 1 + b_dim1];
+ }
+ }
+ if (d__[*n] == 0.) {
+ *info = *n;
+ return 0;
+ }
+ } else {
+ i__1 = *n - 2;
+ for (i__ = 1; i__ <= i__1; ++i__) {
+ if ((d__1 = d__[i__], abs(d__1)) >= (d__2 = dl[i__], abs(d__2))) {
+
+/* No row interchange required */
+
+ if (d__[i__] != 0.) {
+ fact = dl[i__] / d__[i__];
+ d__[i__ + 1] -= fact * du[i__];
+ i__2 = *nrhs;
+ for (j = 1; j <= i__2; ++j) {
+ b[i__ + 1 + j * b_dim1] -= fact * b[i__ + j * b_dim1];
+/* L20: */
+ }
+ } else {
+ *info = i__;
+ return 0;
+ }
+ dl[i__] = 0.;
+ } else {
+
+/* Interchange rows I and I+1 */
+
+ fact = d__[i__] / dl[i__];
+ d__[i__] = dl[i__];
+ temp = d__[i__ + 1];
+ d__[i__ + 1] = du[i__] - fact * temp;
+ dl[i__] = du[i__ + 1];
+ du[i__ + 1] = -fact * dl[i__];
+ du[i__] = temp;
+ i__2 = *nrhs;
+ for (j = 1; j <= i__2; ++j) {
+ temp = b[i__ + j * b_dim1];
+ b[i__ + j * b_dim1] = b[i__ + 1 + j * b_dim1];
+ b[i__ + 1 + j * b_dim1] = temp - fact * b[i__ + 1 + j *
+ b_dim1];
+/* L30: */
+ }
+ }
+/* L40: */
+ }
+ if (*n > 1) {
+ i__ = *n - 1;
+ if ((d__1 = d__[i__], abs(d__1)) >= (d__2 = dl[i__], abs(d__2))) {
+ if (d__[i__] != 0.) {
+ fact = dl[i__] / d__[i__];
+ d__[i__ + 1] -= fact * du[i__];
+ i__1 = *nrhs;
+ for (j = 1; j <= i__1; ++j) {
+ b[i__ + 1 + j * b_dim1] -= fact * b[i__ + j * b_dim1];
+/* L50: */
+ }
+ } else {
+ *info = i__;
+ return 0;
+ }
+ } else {
+ fact = d__[i__] / dl[i__];
+ d__[i__] = dl[i__];
+ temp = d__[i__ + 1];
+ d__[i__ + 1] = du[i__] - fact * temp;
+ du[i__] = temp;
+ i__1 = *nrhs;
+ for (j = 1; j <= i__1; ++j) {
+ temp = b[i__ + j * b_dim1];
+ b[i__ + j * b_dim1] = b[i__ + 1 + j * b_dim1];
+ b[i__ + 1 + j * b_dim1] = temp - fact * b[i__ + 1 + j *
+ b_dim1];
+/* L60: */
+ }
+ }
+ }
+ if (d__[*n] == 0.) {
+ *info = *n;
+ return 0;
+ }
+ }
+
+/* Back solve with the matrix U from the factorization. */
+
+ if (*nrhs <= 2) {
+ j = 1;
+L70:
+ b[*n + j * b_dim1] /= d__[*n];
+ if (*n > 1) {
+ b[*n - 1 + j * b_dim1] = (b[*n - 1 + j * b_dim1] - du[*n - 1] * b[
+ *n + j * b_dim1]) / d__[*n - 1];
+ }
+ for (i__ = *n - 2; i__ >= 1; --i__) {
+ b[i__ + j * b_dim1] = (b[i__ + j * b_dim1] - du[i__] * b[i__ + 1
+ + j * b_dim1] - dl[i__] * b[i__ + 2 + j * b_dim1]) / d__[
+ i__];
+/* L80: */
+ }
+ if (j < *nrhs) {
+ ++j;
+ goto L70;
+ }
+ } else {
+ i__1 = *nrhs;
+ for (j = 1; j <= i__1; ++j) {
+ b[*n + j * b_dim1] /= d__[*n];
+ if (*n > 1) {
+ b[*n - 1 + j * b_dim1] = (b[*n - 1 + j * b_dim1] - du[*n - 1]
+ * b[*n + j * b_dim1]) / d__[*n - 1];
+ }
+ for (i__ = *n - 2; i__ >= 1; --i__) {
+ b[i__ + j * b_dim1] = (b[i__ + j * b_dim1] - du[i__] * b[i__
+ + 1 + j * b_dim1] - dl[i__] * b[i__ + 2 + j * b_dim1])
+ / d__[i__];
+/* L90: */
+ }
+/* L100: */
+ }
+ }
+
+ return 0;
+
+/* End of DGTSV */
+
+} /* dgtsv_ */