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Function dgebrd_

numpy/linalg/lapack_lite/f2c_d_lapack.c:2334–2644  ·  view source on GitHub ↗

Subroutine */

Source from the content-addressed store, hash-verified

2332} /* dgebd2_ */
2333
2334/* Subroutine */ int dgebrd_(integer *m, integer *n, doublereal *a, integer *
2335 lda, doublereal *d__, doublereal *e, doublereal *tauq, doublereal *
2336 taup, doublereal *work, integer *lwork, integer *info)
2337{
2338 /* System generated locals */
2339 integer a_dim1, a_offset, i__1, i__2, i__3, i__4;
2340
2341 /* Local variables */
2342 static integer i__, j, nb, nx;
2343 static doublereal ws;
2344 extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *,
2345 integer *, doublereal *, doublereal *, integer *, doublereal *,
2346 integer *, doublereal *, doublereal *, integer *);
2347 static integer nbmin, iinfo, minmn;
2348 extern /* Subroutine */ int dgebd2_(integer *, integer *, doublereal *,
2349 integer *, doublereal *, doublereal *, doublereal *, doublereal *,
2350 doublereal *, integer *), dlabrd_(integer *, integer *, integer *
2351 , doublereal *, integer *, doublereal *, doublereal *, doublereal
2352 *, doublereal *, doublereal *, integer *, doublereal *, integer *)
2353 , xerbla_(char *, integer *);
2354 extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
2355 integer *, integer *, ftnlen, ftnlen);
2356 static integer ldwrkx, ldwrky, lwkopt;
2357 static logical lquery;
2358
2359
2360/*
2361 -- LAPACK routine (version 3.2) --
2362 -- LAPACK is a software package provided by Univ. of Tennessee, --
2363 -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
2364 November 2006
2365
2366
2367 Purpose
2368 =======
2369
2370 DGEBRD reduces a general real M-by-N matrix A to upper or lower
2371 bidiagonal form B by an orthogonal transformation: Q**T * A * P = B.
2372
2373 If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal.
2374
2375 Arguments
2376 =========
2377
2378 M (input) INTEGER
2379 The number of rows in the matrix A. M >= 0.
2380
2381 N (input) INTEGER
2382 The number of columns in the matrix A. N >= 0.
2383
2384 A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
2385 On entry, the M-by-N general matrix to be reduced.
2386 On exit,
2387 if m >= n, the diagonal and the first superdiagonal are
2388 overwritten with the upper bidiagonal matrix B; the
2389 elements below the diagonal, with the array TAUQ, represent
2390 the orthogonal matrix Q as a product of elementary
2391 reflectors, and the elements above the first superdiagonal,

Callers 2

dgelsd_Function · 0.85
dgesdd_Function · 0.85

Calls 6

ilaenv_Function · 0.85
dlabrd_Function · 0.85
dgemm_Function · 0.85
dgebd2_Function · 0.85
maxFunction · 0.50
minFunction · 0.50

Tested by

no test coverage detected