Subroutine */
| 39267 | } /* dsyevd_ */ |
| 39268 | |
| 39269 | /* Subroutine */ int dsytd2_(char *uplo, integer *n, doublereal *a, integer * |
| 39270 | lda, doublereal *d__, doublereal *e, doublereal *tau, integer *info) |
| 39271 | { |
| 39272 | /* System generated locals */ |
| 39273 | integer a_dim1, a_offset, i__1, i__2, i__3; |
| 39274 | |
| 39275 | /* Local variables */ |
| 39276 | static integer i__; |
| 39277 | extern doublereal ddot_(integer *, doublereal *, integer *, doublereal *, |
| 39278 | integer *); |
| 39279 | static doublereal taui; |
| 39280 | extern /* Subroutine */ int dsyr2_(char *, integer *, doublereal *, |
| 39281 | doublereal *, integer *, doublereal *, integer *, doublereal *, |
| 39282 | integer *); |
| 39283 | static doublereal alpha; |
| 39284 | extern logical lsame_(char *, char *); |
| 39285 | extern /* Subroutine */ int daxpy_(integer *, doublereal *, doublereal *, |
| 39286 | integer *, doublereal *, integer *); |
| 39287 | static logical upper; |
| 39288 | extern /* Subroutine */ int dsymv_(char *, integer *, doublereal *, |
| 39289 | doublereal *, integer *, doublereal *, integer *, doublereal *, |
| 39290 | doublereal *, integer *), dlarfg_(integer *, doublereal *, |
| 39291 | doublereal *, integer *, doublereal *), xerbla_(char *, integer * |
| 39292 | ); |
| 39293 | |
| 39294 | |
| 39295 | /* |
| 39296 | -- LAPACK routine (version 3.2) -- |
| 39297 | -- LAPACK is a software package provided by Univ. of Tennessee, -- |
| 39298 | -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
| 39299 | November 2006 |
| 39300 | |
| 39301 | |
| 39302 | Purpose |
| 39303 | ======= |
| 39304 | |
| 39305 | DSYTD2 reduces a real symmetric matrix A to symmetric tridiagonal |
| 39306 | form T by an orthogonal similarity transformation: Q' * A * Q = T. |
| 39307 | |
| 39308 | Arguments |
| 39309 | ========= |
| 39310 | |
| 39311 | UPLO (input) CHARACTER*1 |
| 39312 | Specifies whether the upper or lower triangular part of the |
| 39313 | symmetric matrix A is stored: |
| 39314 | = 'U': Upper triangular |
| 39315 | = 'L': Lower triangular |
| 39316 | |
| 39317 | N (input) INTEGER |
| 39318 | The order of the matrix A. N >= 0. |
| 39319 | |
| 39320 | A (input/output) DOUBLE PRECISION array, dimension (LDA,N) |
| 39321 | On entry, the symmetric matrix A. If UPLO = 'U', the leading |
| 39322 | n-by-n upper triangular part of A contains the upper |
| 39323 | triangular part of the matrix A, and the strictly lower |
| 39324 | triangular part of A is not referenced. If UPLO = 'L', the |
| 39325 | leading n-by-n lower triangular part of A contains the lower |
| 39326 | triangular part of the matrix A, and the strictly upper |