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Function dlasq1_

numpy/linalg/lapack_lite/f2c_d_lapack.c:29032–29215  ·  view source on GitHub ↗

Subroutine */

Source from the content-addressed store, hash-verified

29030} /* dlaset_ */
29031
29032/* Subroutine */ int dlasq1_(integer *n, doublereal *d__, doublereal *e,
29033 doublereal *work, integer *info)
29034{
29035 /* System generated locals */
29036 integer i__1, i__2;
29037 doublereal d__1, d__2, d__3;
29038
29039 /* Local variables */
29040 static integer i__;
29041 static doublereal eps;
29042 extern /* Subroutine */ int dlas2_(doublereal *, doublereal *, doublereal
29043 *, doublereal *, doublereal *);
29044 static doublereal scale;
29045 static integer iinfo;
29046 static doublereal sigmn;
29047 extern /* Subroutine */ int dcopy_(integer *, doublereal *, integer *,
29048 doublereal *, integer *);
29049 static doublereal sigmx;
29050 extern /* Subroutine */ int dlasq2_(integer *, doublereal *, integer *);
29051
29052 extern /* Subroutine */ int dlascl_(char *, integer *, integer *,
29053 doublereal *, doublereal *, integer *, integer *, doublereal *,
29054 integer *, integer *);
29055 static doublereal safmin;
29056 extern /* Subroutine */ int xerbla_(char *, integer *), dlasrt_(
29057 char *, integer *, doublereal *, integer *);
29058
29059
29060/*
29061 -- LAPACK routine (version 3.2) --
29062
29063 -- Contributed by Osni Marques of the Lawrence Berkeley National --
29064 -- Laboratory and Beresford Parlett of the Univ. of California at --
29065 -- Berkeley --
29066 -- November 2008 --
29067
29068 -- LAPACK is a software package provided by Univ. of Tennessee, --
29069 -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
29070
29071
29072 Purpose
29073 =======
29074
29075 DLASQ1 computes the singular values of a real N-by-N bidiagonal
29076 matrix with diagonal D and off-diagonal E. The singular values
29077 are computed to high relative accuracy, in the absence of
29078 denormalization, underflow and overflow. The algorithm was first
29079 presented in
29080
29081 "Accurate singular values and differential qd algorithms" by K. V.
29082 Fernando and B. N. Parlett, Numer. Math., Vol-67, No. 2, pp. 191-230,
29083 1994,
29084
29085 and the present implementation is described in "An implementation of
29086 the dqds Algorithm (Positive Case)", LAPACK Working Note.
29087
29088 Arguments
29089 =========

Callers 1

dbdsqr_Function · 0.85

Calls 8

absFunction · 0.85
dlas2_Function · 0.85
dlasrt_Function · 0.85
dcopy_Function · 0.85
dlascl_Function · 0.85
dlasq2_Function · 0.85
maxFunction · 0.50
sqrtFunction · 0.50

Tested by

no test coverage detected