mirror of
https://gitlab.com/libeigen/eigen.git
synced 2025-07-23 13:24:28 +08:00
88 lines
2.2 KiB
C++
88 lines
2.2 KiB
C++
|
|
template <typename Scalar>
|
|
void ei_r1mpyq(int m, int n, Scalar *a, int
|
|
lda, const Scalar *v, const Scalar *w)
|
|
{
|
|
/* System generated locals */
|
|
int a_dim1, a_offset;
|
|
|
|
/* Local variables */
|
|
int i, j, nm1, nmj;
|
|
Scalar cos__, sin__, temp;
|
|
|
|
/* Parameter adjustments */
|
|
--w;
|
|
--v;
|
|
a_dim1 = lda;
|
|
a_offset = 1 + a_dim1 * 1;
|
|
a -= a_offset;
|
|
|
|
/* Function Body */
|
|
|
|
/* apply the first set of givens rotations to a. */
|
|
|
|
nm1 = n - 1;
|
|
if (nm1 < 1) {
|
|
/* goto L50; */
|
|
return;
|
|
}
|
|
for (nmj = 1; nmj <= nm1; ++nmj) {
|
|
j = n - nmj;
|
|
if (ei_abs(v[j]) > 1.) {
|
|
cos__ = 1. / v[j];
|
|
}
|
|
if (ei_abs(v[j]) > 1.) {
|
|
/* Computing 2nd power */
|
|
sin__ = ei_sqrt(1. - ei_abs2(cos__));
|
|
}
|
|
if (ei_abs(v[j]) <= 1.) {
|
|
sin__ = v[j];
|
|
}
|
|
if (ei_abs(v[j]) <= 1.) {
|
|
/* Computing 2nd power */
|
|
cos__ = ei_sqrt(1. - ei_abs2(sin__));
|
|
}
|
|
for (i = 1; i <= m; ++i) {
|
|
temp = cos__ * a[i + j * a_dim1] - sin__ * a[i + n * a_dim1];
|
|
a[i + n * a_dim1] = sin__ * a[i + j * a_dim1] + cos__ * a[
|
|
i + n * a_dim1];
|
|
a[i + j * a_dim1] = temp;
|
|
/* L10: */
|
|
}
|
|
/* L20: */
|
|
}
|
|
|
|
/* apply the second set of givens rotations to a. */
|
|
|
|
for (j = 1; j <= nm1; ++j) {
|
|
if (ei_abs(w[j]) > 1.) {
|
|
cos__ = 1. / w[j];
|
|
}
|
|
if (ei_abs(w[j]) > 1.) {
|
|
/* Computing 2nd power */
|
|
sin__ = ei_sqrt(1. - ei_abs2(cos__));
|
|
}
|
|
if (ei_abs(w[j]) <= 1.) {
|
|
sin__ = w[j];
|
|
}
|
|
if (ei_abs(w[j]) <= 1.) {
|
|
/* Computing 2nd power */
|
|
cos__ = ei_sqrt(1. - ei_abs2(sin__));
|
|
}
|
|
for (i = 1; i <= m; ++i) {
|
|
temp = cos__ * a[i + j * a_dim1] + sin__ * a[i + n * a_dim1];
|
|
a[i + n * a_dim1] = -sin__ * a[i + j * a_dim1] + cos__ * a[
|
|
i + n * a_dim1];
|
|
a[i + j * a_dim1] = temp;
|
|
/* L30: */
|
|
}
|
|
/* L40: */
|
|
}
|
|
/* L50: */
|
|
return;
|
|
|
|
/* last card of subroutine r1mpyq. */
|
|
|
|
} /* r1mpyq_ */
|
|
|