#ifdef __cplusplus extern "C" { #endif #include "lmp_f2c.h" static integer c__1 = 1; static integer c__0 = 0; static doublereal c_b8 = 1.; int dlasd8_(integer *icompq, integer *k, doublereal *d__, doublereal *z__, doublereal *vf, doublereal *vl, doublereal *difl, doublereal *difr, integer *lddifr, doublereal *dsigma, doublereal *work, integer *info) { integer difr_dim1, difr_offset, i__1, i__2; doublereal d__1, d__2; double sqrt(doublereal), d_lmp_sign(doublereal *, doublereal *); integer i__, j; doublereal dj, rho; integer iwk1, iwk2, iwk3; extern doublereal ddot_(integer *, doublereal *, integer *, doublereal *, integer *); doublereal temp; extern doublereal dnrm2_(integer *, doublereal *, integer *); integer iwk2i, iwk3i; doublereal diflj, difrj, dsigj; extern int dcopy_(integer *, doublereal *, integer *, doublereal *, integer *); extern doublereal dlamc3_(doublereal *, doublereal *); extern int dlasd4_(integer *, integer *, doublereal *, doublereal *, doublereal *, doublereal *, doublereal *, doublereal *, integer *), dlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublereal *, integer *, integer *, ftnlen), dlaset_(char *, integer *, integer *, doublereal *, doublereal *, doublereal *, integer *, ftnlen), xerbla_(char *, integer *, ftnlen); doublereal dsigjp; --d__; --z__; --vf; --vl; --difl; difr_dim1 = *lddifr; difr_offset = 1 + difr_dim1; difr -= difr_offset; --dsigma; --work; *info = 0; if (*icompq < 0 || *icompq > 1) { *info = -1; } else if (*k < 1) { *info = -2; } else if (*lddifr < *k) { *info = -9; } if (*info != 0) { i__1 = -(*info); xerbla_((char *)"DLASD8", &i__1, (ftnlen)6); return 0; } if (*k == 1) { d__[1] = abs(z__[1]); difl[1] = d__[1]; if (*icompq == 1) { difl[2] = 1.; difr[(difr_dim1 << 1) + 1] = 1.; } return 0; } i__1 = *k; for (i__ = 1; i__ <= i__1; ++i__) { dsigma[i__] = dlamc3_(&dsigma[i__], &dsigma[i__]) - dsigma[i__]; } iwk1 = 1; iwk2 = iwk1 + *k; iwk3 = iwk2 + *k; iwk2i = iwk2 - 1; iwk3i = iwk3 - 1; rho = dnrm2_(k, &z__[1], &c__1); dlascl_((char *)"G", &c__0, &c__0, &rho, &c_b8, k, &c__1, &z__[1], k, info, (ftnlen)1); rho *= rho; dlaset_((char *)"A", k, &c__1, &c_b8, &c_b8, &work[iwk3], k, (ftnlen)1); i__1 = *k; for (j = 1; j <= i__1; ++j) { dlasd4_(k, &j, &dsigma[1], &z__[1], &work[iwk1], &rho, &d__[j], &work[iwk2], info); if (*info != 0) { return 0; } work[iwk3i + j] = work[iwk3i + j] * work[j] * work[iwk2i + j]; difl[j] = -work[j]; difr[j + difr_dim1] = -work[j + 1]; i__2 = j - 1; for (i__ = 1; i__ <= i__2; ++i__) { work[iwk3i + i__] = work[iwk3i + i__] * work[i__] * work[iwk2i + i__] / (dsigma[i__] - dsigma[j]) / (dsigma[i__] + dsigma[j]); } i__2 = *k; for (i__ = j + 1; i__ <= i__2; ++i__) { work[iwk3i + i__] = work[iwk3i + i__] * work[i__] * work[iwk2i + i__] / (dsigma[i__] - dsigma[j]) / (dsigma[i__] + dsigma[j]); } } i__1 = *k; for (i__ = 1; i__ <= i__1; ++i__) { d__2 = sqrt((d__1 = work[iwk3i + i__], abs(d__1))); z__[i__] = d_lmp_sign(&d__2, &z__[i__]); } i__1 = *k; for (j = 1; j <= i__1; ++j) { diflj = difl[j]; dj = d__[j]; dsigj = -dsigma[j]; if (j < *k) { difrj = -difr[j + difr_dim1]; dsigjp = -dsigma[j + 1]; } work[j] = -z__[j] / diflj / (dsigma[j] + dj); i__2 = j - 1; for (i__ = 1; i__ <= i__2; ++i__) { work[i__] = z__[i__] / (dlamc3_(&dsigma[i__], &dsigj) - diflj) / (dsigma[i__] + dj); } i__2 = *k; for (i__ = j + 1; i__ <= i__2; ++i__) { work[i__] = z__[i__] / (dlamc3_(&dsigma[i__], &dsigjp) + difrj) / (dsigma[i__] + dj); } temp = dnrm2_(k, &work[1], &c__1); work[iwk2i + j] = ddot_(k, &work[1], &c__1, &vf[1], &c__1) / temp; work[iwk3i + j] = ddot_(k, &work[1], &c__1, &vl[1], &c__1) / temp; if (*icompq == 1) { difr[j + (difr_dim1 << 1)] = temp; } } dcopy_(k, &work[iwk2], &c__1, &vf[1], &c__1); dcopy_(k, &work[iwk3], &c__1, &vl[1], &c__1); return 0; } #ifdef __cplusplus } #endif