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lammps/lib/linalg/zlanhe.cpp

143 lines
4.8 KiB
C++

#ifdef __cplusplus
extern "C" {
#endif
#include "lmp_f2c.h"
static integer c__1 = 1;
doublereal zlanhe_(char *norm, char *uplo, integer *n, doublecomplex *a, integer *lda,
doublereal *work, ftnlen norm_len, ftnlen uplo_len)
{
integer a_dim1, a_offset, i__1, i__2;
doublereal ret_val, d__1;
double z_lmp_abs(doublecomplex *), sqrt(doublereal);
integer i__, j;
doublereal sum, absa, scale;
extern logical lsame_(char *, char *, ftnlen, ftnlen);
doublereal value;
extern logical disnan_(doublereal *);
extern int zlassq_(integer *, doublecomplex *, integer *, doublereal *, doublereal *);
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
--work;
if (*n == 0) {
value = 0.;
} else if (lsame_(norm, (char *)"M", (ftnlen)1, (ftnlen)1)) {
value = 0.;
if (lsame_(uplo, (char *)"U", (ftnlen)1, (ftnlen)1)) {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = j - 1;
for (i__ = 1; i__ <= i__2; ++i__) {
sum = z_lmp_abs(&a[i__ + j * a_dim1]);
if (value < sum || disnan_(&sum)) {
value = sum;
}
}
i__2 = j + j * a_dim1;
sum = (d__1 = a[i__2].r, abs(d__1));
if (value < sum || disnan_(&sum)) {
value = sum;
}
}
} else {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = j + j * a_dim1;
sum = (d__1 = a[i__2].r, abs(d__1));
if (value < sum || disnan_(&sum)) {
value = sum;
}
i__2 = *n;
for (i__ = j + 1; i__ <= i__2; ++i__) {
sum = z_lmp_abs(&a[i__ + j * a_dim1]);
if (value < sum || disnan_(&sum)) {
value = sum;
}
}
}
}
} else if (lsame_(norm, (char *)"I", (ftnlen)1, (ftnlen)1) || lsame_(norm, (char *)"O", (ftnlen)1, (ftnlen)1) ||
*(unsigned char *)norm == '1') {
value = 0.;
if (lsame_(uplo, (char *)"U", (ftnlen)1, (ftnlen)1)) {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
sum = 0.;
i__2 = j - 1;
for (i__ = 1; i__ <= i__2; ++i__) {
absa = z_lmp_abs(&a[i__ + j * a_dim1]);
sum += absa;
work[i__] += absa;
}
i__2 = j + j * a_dim1;
work[j] = sum + (d__1 = a[i__2].r, abs(d__1));
}
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
sum = work[i__];
if (value < sum || disnan_(&sum)) {
value = sum;
}
}
} else {
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
work[i__] = 0.;
}
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = j + j * a_dim1;
sum = work[j] + (d__1 = a[i__2].r, abs(d__1));
i__2 = *n;
for (i__ = j + 1; i__ <= i__2; ++i__) {
absa = z_lmp_abs(&a[i__ + j * a_dim1]);
sum += absa;
work[i__] += absa;
}
if (value < sum || disnan_(&sum)) {
value = sum;
}
}
}
} else if (lsame_(norm, (char *)"F", (ftnlen)1, (ftnlen)1) || lsame_(norm, (char *)"E", (ftnlen)1, (ftnlen)1)) {
scale = 0.;
sum = 1.;
if (lsame_(uplo, (char *)"U", (ftnlen)1, (ftnlen)1)) {
i__1 = *n;
for (j = 2; j <= i__1; ++j) {
i__2 = j - 1;
zlassq_(&i__2, &a[j * a_dim1 + 1], &c__1, &scale, &sum);
}
} else {
i__1 = *n - 1;
for (j = 1; j <= i__1; ++j) {
i__2 = *n - j;
zlassq_(&i__2, &a[j + 1 + j * a_dim1], &c__1, &scale, &sum);
}
}
sum *= 2;
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
i__2 = i__ + i__ * a_dim1;
if (a[i__2].r != 0.) {
i__2 = i__ + i__ * a_dim1;
absa = (d__1 = a[i__2].r, abs(d__1));
if (scale < absa) {
d__1 = scale / absa;
sum = sum * (d__1 * d__1) + 1.;
scale = absa;
} else {
d__1 = absa / scale;
sum += d__1 * d__1;
}
}
}
value = scale * sqrt(sum);
}
ret_val = value;
return ret_val;
}
#ifdef __cplusplus
}
#endif