149 lines
5.9 KiB
C++
149 lines
5.9 KiB
C++
#ifdef __cplusplus
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extern "C" {
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#endif
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#include "lmp_f2c.h"
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static doublecomplex c_b2 = {0., 0.};
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static integer c__1 = 1;
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int zhetd2_(char *uplo, integer *n, doublecomplex *a, integer *lda, doublereal *d__, doublereal *e,
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doublecomplex *tau, integer *info, ftnlen uplo_len)
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{
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integer a_dim1, a_offset, i__1, i__2, i__3;
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doublereal d__1;
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doublecomplex z__1, z__2, z__3, z__4;
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integer i__;
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doublecomplex taui;
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extern int zher2_(char *, integer *, doublecomplex *, doublecomplex *, integer *,
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doublecomplex *, integer *, doublecomplex *, integer *, ftnlen);
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doublecomplex alpha;
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extern logical lsame_(char *, char *, ftnlen, ftnlen);
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extern VOID zdotc_(doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *,
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integer *);
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extern int zhemv_(char *, integer *, doublecomplex *, doublecomplex *, integer *,
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doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *,
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ftnlen);
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logical upper;
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extern int zaxpy_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *,
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integer *),
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xerbla_(char *, integer *, ftnlen),
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zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *);
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a_dim1 = *lda;
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a_offset = 1 + a_dim1;
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a -= a_offset;
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--d__;
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--e;
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--tau;
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*info = 0;
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upper = lsame_(uplo, (char *)"U", (ftnlen)1, (ftnlen)1);
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if (!upper && !lsame_(uplo, (char *)"L", (ftnlen)1, (ftnlen)1)) {
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*info = -1;
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} else if (*n < 0) {
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*info = -2;
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} else if (*lda < max(1, *n)) {
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*info = -4;
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}
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if (*info != 0) {
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i__1 = -(*info);
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xerbla_((char *)"ZHETD2", &i__1, (ftnlen)6);
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return 0;
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}
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if (*n <= 0) {
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return 0;
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}
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if (upper) {
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i__1 = *n + *n * a_dim1;
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i__2 = *n + *n * a_dim1;
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d__1 = a[i__2].r;
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a[i__1].r = d__1, a[i__1].i = 0.;
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for (i__ = *n - 1; i__ >= 1; --i__) {
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i__1 = i__ + (i__ + 1) * a_dim1;
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alpha.r = a[i__1].r, alpha.i = a[i__1].i;
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zlarfg_(&i__, &alpha, &a[(i__ + 1) * a_dim1 + 1], &c__1, &taui);
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e[i__] = alpha.r;
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if (taui.r != 0. || taui.i != 0.) {
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i__1 = i__ + (i__ + 1) * a_dim1;
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a[i__1].r = 1., a[i__1].i = 0.;
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zhemv_(uplo, &i__, &taui, &a[a_offset], lda, &a[(i__ + 1) * a_dim1 + 1], &c__1,
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&c_b2, &tau[1], &c__1, (ftnlen)1);
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z__3.r = -.5, z__3.i = -0.;
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z__2.r = z__3.r * taui.r - z__3.i * taui.i,
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z__2.i = z__3.r * taui.i + z__3.i * taui.r;
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zdotc_(&z__4, &i__, &tau[1], &c__1, &a[(i__ + 1) * a_dim1 + 1], &c__1);
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z__1.r = z__2.r * z__4.r - z__2.i * z__4.i,
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z__1.i = z__2.r * z__4.i + z__2.i * z__4.r;
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alpha.r = z__1.r, alpha.i = z__1.i;
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zaxpy_(&i__, &alpha, &a[(i__ + 1) * a_dim1 + 1], &c__1, &tau[1], &c__1);
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z__1.r = -1., z__1.i = -0.;
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zher2_(uplo, &i__, &z__1, &a[(i__ + 1) * a_dim1 + 1], &c__1, &tau[1], &c__1,
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&a[a_offset], lda, (ftnlen)1);
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} else {
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i__1 = i__ + i__ * a_dim1;
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i__2 = i__ + i__ * a_dim1;
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d__1 = a[i__2].r;
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a[i__1].r = d__1, a[i__1].i = 0.;
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}
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i__1 = i__ + (i__ + 1) * a_dim1;
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i__2 = i__;
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a[i__1].r = e[i__2], a[i__1].i = 0.;
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i__1 = i__ + 1 + (i__ + 1) * a_dim1;
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d__[i__ + 1] = a[i__1].r;
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i__1 = i__;
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tau[i__1].r = taui.r, tau[i__1].i = taui.i;
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}
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i__1 = a_dim1 + 1;
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d__[1] = a[i__1].r;
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} else {
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i__1 = a_dim1 + 1;
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i__2 = a_dim1 + 1;
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d__1 = a[i__2].r;
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a[i__1].r = d__1, a[i__1].i = 0.;
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i__1 = *n - 1;
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for (i__ = 1; i__ <= i__1; ++i__) {
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i__2 = i__ + 1 + i__ * a_dim1;
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alpha.r = a[i__2].r, alpha.i = a[i__2].i;
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i__2 = *n - i__;
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i__3 = i__ + 2;
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zlarfg_(&i__2, &alpha, &a[min(i__3, *n) + i__ * a_dim1], &c__1, &taui);
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e[i__] = alpha.r;
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if (taui.r != 0. || taui.i != 0.) {
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i__2 = i__ + 1 + i__ * a_dim1;
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a[i__2].r = 1., a[i__2].i = 0.;
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i__2 = *n - i__;
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zhemv_(uplo, &i__2, &taui, &a[i__ + 1 + (i__ + 1) * a_dim1], lda,
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&a[i__ + 1 + i__ * a_dim1], &c__1, &c_b2, &tau[i__], &c__1, (ftnlen)1);
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z__3.r = -.5, z__3.i = -0.;
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z__2.r = z__3.r * taui.r - z__3.i * taui.i,
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z__2.i = z__3.r * taui.i + z__3.i * taui.r;
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i__2 = *n - i__;
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zdotc_(&z__4, &i__2, &tau[i__], &c__1, &a[i__ + 1 + i__ * a_dim1], &c__1);
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z__1.r = z__2.r * z__4.r - z__2.i * z__4.i,
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z__1.i = z__2.r * z__4.i + z__2.i * z__4.r;
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alpha.r = z__1.r, alpha.i = z__1.i;
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i__2 = *n - i__;
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zaxpy_(&i__2, &alpha, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[i__], &c__1);
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i__2 = *n - i__;
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z__1.r = -1., z__1.i = -0.;
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zher2_(uplo, &i__2, &z__1, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[i__], &c__1,
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&a[i__ + 1 + (i__ + 1) * a_dim1], lda, (ftnlen)1);
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} else {
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i__2 = i__ + 1 + (i__ + 1) * a_dim1;
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i__3 = i__ + 1 + (i__ + 1) * a_dim1;
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d__1 = a[i__3].r;
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a[i__2].r = d__1, a[i__2].i = 0.;
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}
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i__2 = i__ + 1 + i__ * a_dim1;
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i__3 = i__;
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a[i__2].r = e[i__3], a[i__2].i = 0.;
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i__2 = i__ + i__ * a_dim1;
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d__[i__] = a[i__2].r;
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i__2 = i__;
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tau[i__2].r = taui.r, tau[i__2].i = taui.i;
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}
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i__1 = *n + *n * a_dim1;
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d__[*n] = a[i__1].r;
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}
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return 0;
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}
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#ifdef __cplusplus
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}
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#endif
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