MCPcopy Create free account
hub / github.com/numpy/numpy / dlabrd_

Function dlabrd_

numpy/linalg/lapack_lite/f2c_d_lapack.c:8021–8422  ·  view source on GitHub ↗

Subroutine */

Source from the content-addressed store, hash-verified

8019} /* dlabad_ */
8020
8021/* Subroutine */ int dlabrd_(integer *m, integer *n, integer *nb, doublereal *
8022 a, integer *lda, doublereal *d__, doublereal *e, doublereal *tauq,
8023 doublereal *taup, doublereal *x, integer *ldx, doublereal *y, integer
8024 *ldy)
8025{
8026 /* System generated locals */
8027 integer a_dim1, a_offset, x_dim1, x_offset, y_dim1, y_offset, i__1, i__2,
8028 i__3;
8029
8030 /* Local variables */
8031 static integer i__;
8032 extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *,
8033 integer *), dgemv_(char *, integer *, integer *, doublereal *,
8034 doublereal *, integer *, doublereal *, integer *, doublereal *,
8035 doublereal *, integer *), dlarfg_(integer *, doublereal *,
8036 doublereal *, integer *, doublereal *);
8037
8038
8039/*
8040 -- LAPACK auxiliary routine (version 3.2) --
8041 -- LAPACK is a software package provided by Univ. of Tennessee, --
8042 -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
8043 November 2006
8044
8045
8046 Purpose
8047 =======
8048
8049 DLABRD reduces the first NB rows and columns of a real general
8050 m by n matrix A to upper or lower bidiagonal form by an orthogonal
8051 transformation Q' * A * P, and returns the matrices X and Y which
8052 are needed to apply the transformation to the unreduced part of A.
8053
8054 If m >= n, A is reduced to upper bidiagonal form; if m < n, to lower
8055 bidiagonal form.
8056
8057 This is an auxiliary routine called by DGEBRD
8058
8059 Arguments
8060 =========
8061
8062 M (input) INTEGER
8063 The number of rows in the matrix A.
8064
8065 N (input) INTEGER
8066 The number of columns in the matrix A.
8067
8068 NB (input) INTEGER
8069 The number of leading rows and columns of A to be reduced.
8070
8071 A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
8072 On entry, the m by n general matrix to be reduced.
8073 On exit, the first NB rows and columns of the matrix are
8074 overwritten; the rest of the array is unchanged.
8075 If m >= n, elements on and below the diagonal in the first NB
8076 columns, with the array TAUQ, represent the orthogonal
8077 matrix Q as a product of elementary reflectors; and
8078 elements above the diagonal in the first NB rows, with the

Callers 1

dgebrd_Function · 0.85

Calls 4

dgemv_Function · 0.85
dlarfg_Function · 0.85
dscal_Function · 0.85
minFunction · 0.50

Tested by

no test coverage detected