#ifdef __cplusplus extern "C" { #endif #include "lmp_f2c.h" static integer c__1 = 1; static integer c_n1 = -1; static integer c__0 = 0; static doublereal c_b17 = 1.; int dsyev_(char *jobz, char *uplo, integer *n, doublereal *a, integer *lda, doublereal *w, doublereal *work, integer *lwork, integer *info, ftnlen jobz_len, ftnlen uplo_len) { integer a_dim1, a_offset, i__1, i__2; doublereal d__1; double sqrt(doublereal); integer nb; doublereal eps; integer inde; doublereal anrm; integer imax; doublereal rmin, rmax; extern int dscal_(integer *, doublereal *, doublereal *, integer *); doublereal sigma; extern logical lsame_(char *, char *, ftnlen, ftnlen); integer iinfo; logical lower, wantz; extern doublereal dlamch_(char *, ftnlen); integer iscale; extern int dlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublereal *, integer *, integer *, ftnlen); doublereal safmin; extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern int xerbla_(char *, integer *, ftnlen); doublereal bignum; integer indtau; extern int dsterf_(integer *, doublereal *, doublereal *, integer *); extern doublereal dlansy_(char *, char *, integer *, doublereal *, integer *, doublereal *, ftnlen, ftnlen); integer indwrk; extern int dorgtr_(char *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, integer *, ftnlen), dsteqr_(char *, integer *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, integer *, ftnlen), dsytrd_(char *, integer *, doublereal *, integer *, doublereal *, doublereal *, doublereal *, doublereal *, integer *, integer *, ftnlen); integer llwork; doublereal smlnum; integer lwkopt; logical lquery; a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --w; --work; wantz = lsame_(jobz, (char *)"V", (ftnlen)1, (ftnlen)1); lower = lsame_(uplo, (char *)"L", (ftnlen)1, (ftnlen)1); lquery = *lwork == -1; *info = 0; if (!(wantz || lsame_(jobz, (char *)"N", (ftnlen)1, (ftnlen)1))) { *info = -1; } else if (!(lower || lsame_(uplo, (char *)"U", (ftnlen)1, (ftnlen)1))) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*lda < max(1, *n)) { *info = -5; } if (*info == 0) { nb = ilaenv_(&c__1, (char *)"DSYTRD", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); i__1 = 1, i__2 = (nb + 2) * *n; lwkopt = max(i__1, i__2); work[1] = (doublereal)lwkopt; i__1 = 1, i__2 = *n * 3 - 1; if (*lwork < max(i__1, i__2) && !lquery) { *info = -8; } } if (*info != 0) { i__1 = -(*info); xerbla_((char *)"DSYEV ", &i__1, (ftnlen)6); return 0; } else if (lquery) { return 0; } if (*n == 0) { return 0; } if (*n == 1) { w[1] = a[a_dim1 + 1]; work[1] = 2.; if (wantz) { a[a_dim1 + 1] = 1.; } return 0; } safmin = dlamch_((char *)"Safe minimum", (ftnlen)12); eps = dlamch_((char *)"Precision", (ftnlen)9); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = sqrt(smlnum); rmax = sqrt(bignum); anrm = dlansy_((char *)"M", uplo, n, &a[a_offset], lda, &work[1], (ftnlen)1, (ftnlen)1); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { dlascl_(uplo, &c__0, &c__0, &c_b17, &sigma, n, n, &a[a_offset], lda, info, (ftnlen)1); } inde = 1; indtau = inde + *n; indwrk = indtau + *n; llwork = *lwork - indwrk + 1; dsytrd_(uplo, n, &a[a_offset], lda, &w[1], &work[inde], &work[indtau], &work[indwrk], &llwork, &iinfo, (ftnlen)1); if (!wantz) { dsterf_(n, &w[1], &work[inde], info); } else { dorgtr_(uplo, n, &a[a_offset], lda, &work[indtau], &work[indwrk], &llwork, &iinfo, (ftnlen)1); dsteqr_(jobz, n, &w[1], &work[inde], &a[a_offset], lda, &work[indtau], info, (ftnlen)1); } if (iscale == 1) { if (*info == 0) { imax = *n; } else { imax = *info - 1; } d__1 = 1. / sigma; dscal_(&imax, &d__1, &w[1], &c__1); } work[1] = (doublereal)lwkopt; return 0; } #ifdef __cplusplus } #endif