lammps/lib/linalg/dorgl2.cpp

74 lines
2.0 KiB
C++

#ifdef __cplusplus
extern "C" {
#endif
#include "lmp_f2c.h"
int dorgl2_(integer *m, integer *n, integer *k, doublereal *a, integer *lda, doublereal *tau,
doublereal *work, integer *info)
{
integer a_dim1, a_offset, i__1, i__2;
doublereal d__1;
integer i__, j, l;
extern int dscal_(integer *, doublereal *, doublereal *, integer *),
dlarf_(char *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *,
integer *, doublereal *, ftnlen),
xerbla_(char *, integer *, ftnlen);
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
--tau;
--work;
*info = 0;
if (*m < 0) {
*info = -1;
} else if (*n < *m) {
*info = -2;
} else if (*k < 0 || *k > *m) {
*info = -3;
} else if (*lda < max(1, *m)) {
*info = -5;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_((char *)"DORGL2", &i__1, (ftnlen)6);
return 0;
}
if (*m <= 0) {
return 0;
}
if (*k < *m) {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (l = *k + 1; l <= i__2; ++l) {
a[l + j * a_dim1] = 0.;
}
if (j > *k && j <= *m) {
a[j + j * a_dim1] = 1.;
}
}
}
for (i__ = *k; i__ >= 1; --i__) {
if (i__ < *n) {
if (i__ < *m) {
a[i__ + i__ * a_dim1] = 1.;
i__1 = *m - i__;
i__2 = *n - i__ + 1;
dlarf_((char *)"Right", &i__1, &i__2, &a[i__ + i__ * a_dim1], lda, &tau[i__],
&a[i__ + 1 + i__ * a_dim1], lda, &work[1], (ftnlen)5);
}
i__1 = *n - i__;
d__1 = -tau[i__];
dscal_(&i__1, &d__1, &a[i__ + (i__ + 1) * a_dim1], lda);
}
a[i__ + i__ * a_dim1] = 1. - tau[i__];
i__1 = i__ - 1;
for (l = 1; l <= i__1; ++l) {
a[i__ + l * a_dim1] = 0.;
}
}
return 0;
}
#ifdef __cplusplus
}
#endif