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lammps/lib/linalg/zsytf2.cpp
2024-11-09 04:14:11 -05:00

357 lines
15 KiB
C++

#ifdef __cplusplus
extern "C" {
#endif
#include "lmp_f2c.h"
static doublecomplex c_b1 = {1., 0.};
static integer c__1 = 1;
int zsytf2_(char *uplo, integer *n, doublecomplex *a, integer *lda, integer *ipiv, integer *info,
ftnlen uplo_len)
{
integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5, i__6;
doublereal d__1, d__2, d__3, d__4;
doublecomplex z__1, z__2, z__3, z__4;
double sqrt(doublereal), d_lmp_imag(doublecomplex *);
void z_lmp_div(doublecomplex *, doublecomplex *, doublecomplex *);
integer i__, j, k;
doublecomplex t, r1, d11, d12, d21, d22;
integer kk, kp;
doublecomplex wk, wkm1, wkp1;
integer imax, jmax;
extern int zsyr_(char *, integer *, doublecomplex *, doublecomplex *, integer *,
doublecomplex *, integer *, ftnlen);
doublereal alpha;
extern logical lsame_(char *, char *, ftnlen, ftnlen);
extern int zscal_(integer *, doublecomplex *, doublecomplex *, integer *);
integer kstep;
logical upper;
extern int zswap_(integer *, doublecomplex *, integer *, doublecomplex *, integer *);
doublereal absakk;
extern logical disnan_(doublereal *);
extern int xerbla_(char *, integer *, ftnlen);
doublereal colmax;
extern integer izamax_(integer *, doublecomplex *, integer *);
doublereal rowmax;
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
--ipiv;
*info = 0;
upper = lsame_(uplo, (char *)"U", (ftnlen)1, (ftnlen)1);
if (!upper && !lsame_(uplo, (char *)"L", (ftnlen)1, (ftnlen)1)) {
*info = -1;
} else if (*n < 0) {
*info = -2;
} else if (*lda < max(1, *n)) {
*info = -4;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_((char *)"ZSYTF2", &i__1, (ftnlen)6);
return 0;
}
alpha = (sqrt(17.) + 1.) / 8.;
if (upper) {
k = *n;
L10:
if (k < 1) {
goto L70;
}
kstep = 1;
i__1 = k + k * a_dim1;
absakk = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_lmp_imag(&a[k + k * a_dim1]), abs(d__2));
if (k > 1) {
i__1 = k - 1;
imax = izamax_(&i__1, &a[k * a_dim1 + 1], &c__1);
i__1 = imax + k * a_dim1;
colmax =
(d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_lmp_imag(&a[imax + k * a_dim1]), abs(d__2));
} else {
colmax = 0.;
}
if (max(absakk, colmax) == 0. || disnan_(&absakk)) {
if (*info == 0) {
*info = k;
}
kp = k;
} else {
if (absakk >= alpha * colmax) {
kp = k;
} else {
i__1 = k - imax;
jmax = imax + izamax_(&i__1, &a[imax + (imax + 1) * a_dim1], lda);
i__1 = imax + jmax * a_dim1;
rowmax = (d__1 = a[i__1].r, abs(d__1)) +
(d__2 = d_lmp_imag(&a[imax + jmax * a_dim1]), abs(d__2));
if (imax > 1) {
i__1 = imax - 1;
jmax = izamax_(&i__1, &a[imax * a_dim1 + 1], &c__1);
i__1 = jmax + imax * a_dim1;
d__3 = rowmax, d__4 = (d__1 = a[i__1].r, abs(d__1)) +
(d__2 = d_lmp_imag(&a[jmax + imax * a_dim1]), abs(d__2));
rowmax = max(d__3, d__4);
}
if (absakk >= alpha * colmax * (colmax / rowmax)) {
kp = k;
} else {
i__1 = imax + imax * a_dim1;
if ((d__1 = a[i__1].r, abs(d__1)) +
(d__2 = d_lmp_imag(&a[imax + imax * a_dim1]), abs(d__2)) >=
alpha * rowmax) {
kp = imax;
} else {
kp = imax;
kstep = 2;
}
}
}
kk = k - kstep + 1;
if (kp != kk) {
i__1 = kp - 1;
zswap_(&i__1, &a[kk * a_dim1 + 1], &c__1, &a[kp * a_dim1 + 1], &c__1);
i__1 = kk - kp - 1;
zswap_(&i__1, &a[kp + 1 + kk * a_dim1], &c__1, &a[kp + (kp + 1) * a_dim1], lda);
i__1 = kk + kk * a_dim1;
t.r = a[i__1].r, t.i = a[i__1].i;
i__1 = kk + kk * a_dim1;
i__2 = kp + kp * a_dim1;
a[i__1].r = a[i__2].r, a[i__1].i = a[i__2].i;
i__1 = kp + kp * a_dim1;
a[i__1].r = t.r, a[i__1].i = t.i;
if (kstep == 2) {
i__1 = k - 1 + k * a_dim1;
t.r = a[i__1].r, t.i = a[i__1].i;
i__1 = k - 1 + k * a_dim1;
i__2 = kp + k * a_dim1;
a[i__1].r = a[i__2].r, a[i__1].i = a[i__2].i;
i__1 = kp + k * a_dim1;
a[i__1].r = t.r, a[i__1].i = t.i;
}
}
if (kstep == 1) {
z_lmp_div(&z__1, &c_b1, &a[k + k * a_dim1]);
r1.r = z__1.r, r1.i = z__1.i;
i__1 = k - 1;
z__1.r = -r1.r, z__1.i = -r1.i;
zsyr_(uplo, &i__1, &z__1, &a[k * a_dim1 + 1], &c__1, &a[a_offset], lda, (ftnlen)1);
i__1 = k - 1;
zscal_(&i__1, &r1, &a[k * a_dim1 + 1], &c__1);
} else {
if (k > 2) {
i__1 = k - 1 + k * a_dim1;
d12.r = a[i__1].r, d12.i = a[i__1].i;
z_lmp_div(&z__1, &a[k - 1 + (k - 1) * a_dim1], &d12);
d22.r = z__1.r, d22.i = z__1.i;
z_lmp_div(&z__1, &a[k + k * a_dim1], &d12);
d11.r = z__1.r, d11.i = z__1.i;
z__3.r = d11.r * d22.r - d11.i * d22.i, z__3.i = d11.r * d22.i + d11.i * d22.r;
z__2.r = z__3.r - 1., z__2.i = z__3.i - 0.;
z_lmp_div(&z__1, &c_b1, &z__2);
t.r = z__1.r, t.i = z__1.i;
z_lmp_div(&z__1, &t, &d12);
d12.r = z__1.r, d12.i = z__1.i;
for (j = k - 2; j >= 1; --j) {
i__1 = j + (k - 1) * a_dim1;
z__3.r = d11.r * a[i__1].r - d11.i * a[i__1].i,
z__3.i = d11.r * a[i__1].i + d11.i * a[i__1].r;
i__2 = j + k * a_dim1;
z__2.r = z__3.r - a[i__2].r, z__2.i = z__3.i - a[i__2].i;
z__1.r = d12.r * z__2.r - d12.i * z__2.i,
z__1.i = d12.r * z__2.i + d12.i * z__2.r;
wkm1.r = z__1.r, wkm1.i = z__1.i;
i__1 = j + k * a_dim1;
z__3.r = d22.r * a[i__1].r - d22.i * a[i__1].i,
z__3.i = d22.r * a[i__1].i + d22.i * a[i__1].r;
i__2 = j + (k - 1) * a_dim1;
z__2.r = z__3.r - a[i__2].r, z__2.i = z__3.i - a[i__2].i;
z__1.r = d12.r * z__2.r - d12.i * z__2.i,
z__1.i = d12.r * z__2.i + d12.i * z__2.r;
wk.r = z__1.r, wk.i = z__1.i;
for (i__ = j; i__ >= 1; --i__) {
i__1 = i__ + j * a_dim1;
i__2 = i__ + j * a_dim1;
i__3 = i__ + k * a_dim1;
z__3.r = a[i__3].r * wk.r - a[i__3].i * wk.i,
z__3.i = a[i__3].r * wk.i + a[i__3].i * wk.r;
z__2.r = a[i__2].r - z__3.r, z__2.i = a[i__2].i - z__3.i;
i__4 = i__ + (k - 1) * a_dim1;
z__4.r = a[i__4].r * wkm1.r - a[i__4].i * wkm1.i,
z__4.i = a[i__4].r * wkm1.i + a[i__4].i * wkm1.r;
z__1.r = z__2.r - z__4.r, z__1.i = z__2.i - z__4.i;
a[i__1].r = z__1.r, a[i__1].i = z__1.i;
}
i__1 = j + k * a_dim1;
a[i__1].r = wk.r, a[i__1].i = wk.i;
i__1 = j + (k - 1) * a_dim1;
a[i__1].r = wkm1.r, a[i__1].i = wkm1.i;
}
}
}
}
if (kstep == 1) {
ipiv[k] = kp;
} else {
ipiv[k] = -kp;
ipiv[k - 1] = -kp;
}
k -= kstep;
goto L10;
} else {
k = 1;
L40:
if (k > *n) {
goto L70;
}
kstep = 1;
i__1 = k + k * a_dim1;
absakk = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_lmp_imag(&a[k + k * a_dim1]), abs(d__2));
if (k < *n) {
i__1 = *n - k;
imax = k + izamax_(&i__1, &a[k + 1 + k * a_dim1], &c__1);
i__1 = imax + k * a_dim1;
colmax =
(d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_lmp_imag(&a[imax + k * a_dim1]), abs(d__2));
} else {
colmax = 0.;
}
if (max(absakk, colmax) == 0. || disnan_(&absakk)) {
if (*info == 0) {
*info = k;
}
kp = k;
} else {
if (absakk >= alpha * colmax) {
kp = k;
} else {
i__1 = imax - k;
jmax = k - 1 + izamax_(&i__1, &a[imax + k * a_dim1], lda);
i__1 = imax + jmax * a_dim1;
rowmax = (d__1 = a[i__1].r, abs(d__1)) +
(d__2 = d_lmp_imag(&a[imax + jmax * a_dim1]), abs(d__2));
if (imax < *n) {
i__1 = *n - imax;
jmax = imax + izamax_(&i__1, &a[imax + 1 + imax * a_dim1], &c__1);
i__1 = jmax + imax * a_dim1;
d__3 = rowmax, d__4 = (d__1 = a[i__1].r, abs(d__1)) +
(d__2 = d_lmp_imag(&a[jmax + imax * a_dim1]), abs(d__2));
rowmax = max(d__3, d__4);
}
if (absakk >= alpha * colmax * (colmax / rowmax)) {
kp = k;
} else {
i__1 = imax + imax * a_dim1;
if ((d__1 = a[i__1].r, abs(d__1)) +
(d__2 = d_lmp_imag(&a[imax + imax * a_dim1]), abs(d__2)) >=
alpha * rowmax) {
kp = imax;
} else {
kp = imax;
kstep = 2;
}
}
}
kk = k + kstep - 1;
if (kp != kk) {
if (kp < *n) {
i__1 = *n - kp;
zswap_(&i__1, &a[kp + 1 + kk * a_dim1], &c__1, &a[kp + 1 + kp * a_dim1], &c__1);
}
i__1 = kp - kk - 1;
zswap_(&i__1, &a[kk + 1 + kk * a_dim1], &c__1, &a[kp + (kk + 1) * a_dim1], lda);
i__1 = kk + kk * a_dim1;
t.r = a[i__1].r, t.i = a[i__1].i;
i__1 = kk + kk * a_dim1;
i__2 = kp + kp * a_dim1;
a[i__1].r = a[i__2].r, a[i__1].i = a[i__2].i;
i__1 = kp + kp * a_dim1;
a[i__1].r = t.r, a[i__1].i = t.i;
if (kstep == 2) {
i__1 = k + 1 + k * a_dim1;
t.r = a[i__1].r, t.i = a[i__1].i;
i__1 = k + 1 + k * a_dim1;
i__2 = kp + k * a_dim1;
a[i__1].r = a[i__2].r, a[i__1].i = a[i__2].i;
i__1 = kp + k * a_dim1;
a[i__1].r = t.r, a[i__1].i = t.i;
}
}
if (kstep == 1) {
if (k < *n) {
z_lmp_div(&z__1, &c_b1, &a[k + k * a_dim1]);
r1.r = z__1.r, r1.i = z__1.i;
i__1 = *n - k;
z__1.r = -r1.r, z__1.i = -r1.i;
zsyr_(uplo, &i__1, &z__1, &a[k + 1 + k * a_dim1], &c__1,
&a[k + 1 + (k + 1) * a_dim1], lda, (ftnlen)1);
i__1 = *n - k;
zscal_(&i__1, &r1, &a[k + 1 + k * a_dim1], &c__1);
}
} else {
if (k < *n - 1) {
i__1 = k + 1 + k * a_dim1;
d21.r = a[i__1].r, d21.i = a[i__1].i;
z_lmp_div(&z__1, &a[k + 1 + (k + 1) * a_dim1], &d21);
d11.r = z__1.r, d11.i = z__1.i;
z_lmp_div(&z__1, &a[k + k * a_dim1], &d21);
d22.r = z__1.r, d22.i = z__1.i;
z__3.r = d11.r * d22.r - d11.i * d22.i, z__3.i = d11.r * d22.i + d11.i * d22.r;
z__2.r = z__3.r - 1., z__2.i = z__3.i - 0.;
z_lmp_div(&z__1, &c_b1, &z__2);
t.r = z__1.r, t.i = z__1.i;
z_lmp_div(&z__1, &t, &d21);
d21.r = z__1.r, d21.i = z__1.i;
i__1 = *n;
for (j = k + 2; j <= i__1; ++j) {
i__2 = j + k * a_dim1;
z__3.r = d11.r * a[i__2].r - d11.i * a[i__2].i,
z__3.i = d11.r * a[i__2].i + d11.i * a[i__2].r;
i__3 = j + (k + 1) * a_dim1;
z__2.r = z__3.r - a[i__3].r, z__2.i = z__3.i - a[i__3].i;
z__1.r = d21.r * z__2.r - d21.i * z__2.i,
z__1.i = d21.r * z__2.i + d21.i * z__2.r;
wk.r = z__1.r, wk.i = z__1.i;
i__2 = j + (k + 1) * a_dim1;
z__3.r = d22.r * a[i__2].r - d22.i * a[i__2].i,
z__3.i = d22.r * a[i__2].i + d22.i * a[i__2].r;
i__3 = j + k * a_dim1;
z__2.r = z__3.r - a[i__3].r, z__2.i = z__3.i - a[i__3].i;
z__1.r = d21.r * z__2.r - d21.i * z__2.i,
z__1.i = d21.r * z__2.i + d21.i * z__2.r;
wkp1.r = z__1.r, wkp1.i = z__1.i;
i__2 = *n;
for (i__ = j; i__ <= i__2; ++i__) {
i__3 = i__ + j * a_dim1;
i__4 = i__ + j * a_dim1;
i__5 = i__ + k * a_dim1;
z__3.r = a[i__5].r * wk.r - a[i__5].i * wk.i,
z__3.i = a[i__5].r * wk.i + a[i__5].i * wk.r;
z__2.r = a[i__4].r - z__3.r, z__2.i = a[i__4].i - z__3.i;
i__6 = i__ + (k + 1) * a_dim1;
z__4.r = a[i__6].r * wkp1.r - a[i__6].i * wkp1.i,
z__4.i = a[i__6].r * wkp1.i + a[i__6].i * wkp1.r;
z__1.r = z__2.r - z__4.r, z__1.i = z__2.i - z__4.i;
a[i__3].r = z__1.r, a[i__3].i = z__1.i;
}
i__2 = j + k * a_dim1;
a[i__2].r = wk.r, a[i__2].i = wk.i;
i__2 = j + (k + 1) * a_dim1;
a[i__2].r = wkp1.r, a[i__2].i = wkp1.i;
}
}
}
}
if (kstep == 1) {
ipiv[k] = kp;
} else {
ipiv[k] = -kp;
ipiv[k + 1] = -kp;
}
k += kstep;
goto L40;
}
L70:
return 0;
}
#ifdef __cplusplus
}
#endif