96 lines
3.1 KiB
C++
96 lines
3.1 KiB
C++
#ifdef __cplusplus
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extern "C" {
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#endif
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#include "lmp_f2c.h"
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static integer c__1 = 1;
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static doublereal c_b10 = -1.;
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static doublereal c_b12 = 1.;
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int dpotf2_(char *uplo, integer *n, doublereal *a, integer *lda, integer *info, ftnlen uplo_len)
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{
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integer a_dim1, a_offset, i__1, i__2, i__3;
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doublereal d__1;
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double sqrt(doublereal);
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integer j;
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doublereal ajj;
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extern doublereal ddot_(integer *, doublereal *, integer *, doublereal *, integer *);
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extern int dscal_(integer *, doublereal *, doublereal *, integer *);
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extern logical lsame_(char *, char *, ftnlen, ftnlen);
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extern int dgemv_(char *, integer *, integer *, doublereal *, doublereal *, integer *,
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doublereal *, integer *, doublereal *, doublereal *, integer *, ftnlen);
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logical upper;
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extern logical disnan_(doublereal *);
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extern int xerbla_(char *, integer *, ftnlen);
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a_dim1 = *lda;
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a_offset = 1 + a_dim1;
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a -= a_offset;
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*info = 0;
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upper = lsame_(uplo, (char *)"U", (ftnlen)1, (ftnlen)1);
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if (!upper && !lsame_(uplo, (char *)"L", (ftnlen)1, (ftnlen)1)) {
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*info = -1;
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} else if (*n < 0) {
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*info = -2;
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} else if (*lda < max(1, *n)) {
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*info = -4;
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}
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if (*info != 0) {
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i__1 = -(*info);
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xerbla_((char *)"DPOTF2", &i__1, (ftnlen)6);
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return 0;
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}
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if (*n == 0) {
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return 0;
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}
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if (upper) {
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i__1 = *n;
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for (j = 1; j <= i__1; ++j) {
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i__2 = j - 1;
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ajj = a[j + j * a_dim1] -
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ddot_(&i__2, &a[j * a_dim1 + 1], &c__1, &a[j * a_dim1 + 1], &c__1);
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if (ajj <= 0. || disnan_(&ajj)) {
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a[j + j * a_dim1] = ajj;
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goto L30;
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}
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ajj = sqrt(ajj);
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a[j + j * a_dim1] = ajj;
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if (j < *n) {
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i__2 = j - 1;
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i__3 = *n - j;
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dgemv_((char *)"T", &i__2, &i__3, &c_b10, &a[(j + 1) * a_dim1 + 1], lda, &a[j * a_dim1 + 1],
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&c__1, &c_b12, &a[j + (j + 1) * a_dim1], lda, (ftnlen)1);
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i__2 = *n - j;
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d__1 = 1. / ajj;
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dscal_(&i__2, &d__1, &a[j + (j + 1) * a_dim1], lda);
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}
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}
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} else {
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i__1 = *n;
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for (j = 1; j <= i__1; ++j) {
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i__2 = j - 1;
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ajj = a[j + j * a_dim1] - ddot_(&i__2, &a[j + a_dim1], lda, &a[j + a_dim1], lda);
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if (ajj <= 0. || disnan_(&ajj)) {
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a[j + j * a_dim1] = ajj;
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goto L30;
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}
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ajj = sqrt(ajj);
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a[j + j * a_dim1] = ajj;
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if (j < *n) {
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i__2 = *n - j;
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i__3 = j - 1;
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dgemv_((char *)"N", &i__2, &i__3, &c_b10, &a[j + 1 + a_dim1], lda, &a[j + a_dim1], lda,
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&c_b12, &a[j + 1 + j * a_dim1], &c__1, (ftnlen)1);
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i__2 = *n - j;
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d__1 = 1. / ajj;
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dscal_(&i__2, &d__1, &a[j + 1 + j * a_dim1], &c__1);
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}
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}
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}
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goto L40;
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L30:
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*info = j;
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L40:
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return 0;
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}
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#ifdef __cplusplus
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}
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#endif
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