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lammps/lib/linalg/zung2l.cpp

77 lines
2.2 KiB
C++

#ifdef __cplusplus
extern "C" {
#endif
#include "lmp_f2c.h"
static integer c__1 = 1;
int zung2l_(integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau,
doublecomplex *work, integer *info)
{
integer a_dim1, a_offset, i__1, i__2, i__3;
doublecomplex z__1;
integer i__, j, l, ii;
extern int zscal_(integer *, doublecomplex *, doublecomplex *, integer *),
xerbla_(char *, integer *, ftnlen),
zlarf1l_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *,
doublecomplex *, integer *, doublecomplex *, ftnlen);
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
--tau;
--work;
*info = 0;
if (*m < 0) {
*info = -1;
} else if (*n < 0 || *n > *m) {
*info = -2;
} else if (*k < 0 || *k > *n) {
*info = -3;
} else if (*lda < max(1, *m)) {
*info = -5;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_((char *)"ZUNG2L", &i__1, (ftnlen)6);
return 0;
}
if (*n <= 0) {
return 0;
}
i__1 = *n - *k;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (l = 1; l <= i__2; ++l) {
i__3 = l + j * a_dim1;
a[i__3].r = 0., a[i__3].i = 0.;
}
i__2 = *m - *n + j + j * a_dim1;
a[i__2].r = 1., a[i__2].i = 0.;
}
i__1 = *k;
for (i__ = 1; i__ <= i__1; ++i__) {
ii = *n - *k + i__;
i__2 = *m - *n + ii + ii * a_dim1;
a[i__2].r = 1., a[i__2].i = 0.;
i__2 = *m - *n + ii;
i__3 = ii - 1;
zlarf1l_((char *)"L", &i__2, &i__3, &a[ii * a_dim1 + 1], &c__1, &tau[i__], &a[a_offset], lda,
&work[1], (ftnlen)1);
i__2 = *m - *n + ii - 1;
i__3 = i__;
z__1.r = -tau[i__3].r, z__1.i = -tau[i__3].i;
zscal_(&i__2, &z__1, &a[ii * a_dim1 + 1], &c__1);
i__2 = *m - *n + ii + ii * a_dim1;
i__3 = i__;
z__1.r = 1. - tau[i__3].r, z__1.i = 0. - tau[i__3].i;
a[i__2].r = z__1.r, a[i__2].i = z__1.i;
i__2 = *m;
for (l = *m - *n + ii + 1; l <= i__2; ++l) {
i__3 = l + ii * a_dim1;
a[i__3].r = 0., a[i__3].i = 0.;
}
}
return 0;
}
#ifdef __cplusplus
}
#endif