Add graph references
This commit is contained in:
Abdelrahman Said
+462
@@ -0,0 +1,462 @@
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/* -- translated by f2c (version 20240504).
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You must link the resulting object file with libf2c:
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on Microsoft Windows system, link with libf2c.lib;
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on Linux or Unix systems, link with .../path/to/libf2c.a -lm
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or, if you install libf2c.a in a standard place, with -lf2c -lm
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-- in that order, at the end of the command line, as in
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cc *.o -lf2c -lm
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Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
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http://www.netlib.org/f2c/libf2c.zip
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*/
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#include "f2c.h"
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/* > \brief \b DLASQ5 computes one dqds transform in ping-pong form. Used by sbdsqr and sstegr.
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=========== DOCUMENTATION ===========
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Online html documentation available at
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http://www.netlib.org/lapack/explore-html/
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> \htmlonly
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> Download DLASQ5 + dependencies
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> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlasq5.
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f">
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> [TGZ]</a>
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> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlasq5.
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f">
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> [ZIP]</a>
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> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlasq5.
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f">
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> [TXT]</a>
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> \endhtmlonly
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Definition:
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===========
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SUBROUTINE DLASQ5( I0, N0, Z, PP, TAU, SIGMA, DMIN, DMIN1, DMIN2, DN,
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DNM1, DNM2, IEEE, EPS )
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LOGICAL IEEE
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INTEGER I0, N0, PP
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DOUBLE PRECISION DMIN, DMIN1, DMIN2, DN, DNM1, DNM2, TAU, SIGMA, EPS
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DOUBLE PRECISION Z( * )
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> \par Purpose:
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=============
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>
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> \verbatim
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>
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> DLASQ5 computes one dqds transform in ping-pong form, one
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> version for IEEE machines another for non IEEE machines.
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> \endverbatim
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Arguments:
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==========
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> \param[in] I0
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> \verbatim
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> I0 is INTEGER
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> First index.
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> \endverbatim
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>
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> \param[in] N0
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> \verbatim
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> N0 is INTEGER
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> Last index.
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> \endverbatim
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>
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> \param[in] Z
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> \verbatim
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> Z is DOUBLE PRECISION array, dimension ( 4*N )
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> Z holds the qd array. EMIN is stored in Z(4*N0) to avoid
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> an extra argument.
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> \endverbatim
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>
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> \param[in] PP
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> \verbatim
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> PP is INTEGER
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> PP=0 for ping, PP=1 for pong.
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> \endverbatim
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>
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> \param[in] TAU
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> \verbatim
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> TAU is DOUBLE PRECISION
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> This is the shift.
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> \endverbatim
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>
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> \param[in] SIGMA
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> \verbatim
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> SIGMA is DOUBLE PRECISION
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> This is the accumulated shift up to this step.
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> \endverbatim
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>
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> \param[out] DMIN
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> \verbatim
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> DMIN is DOUBLE PRECISION
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> Minimum value of d.
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> \endverbatim
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>
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> \param[out] DMIN1
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> \verbatim
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> DMIN1 is DOUBLE PRECISION
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> Minimum value of d, excluding D( N0 ).
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> \endverbatim
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>
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> \param[out] DMIN2
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> \verbatim
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> DMIN2 is DOUBLE PRECISION
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> Minimum value of d, excluding D( N0 ) and D( N0-1 ).
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> \endverbatim
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>
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> \param[out] DN
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> \verbatim
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> DN is DOUBLE PRECISION
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> d(N0), the last value of d.
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> \endverbatim
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>
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> \param[out] DNM1
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> \verbatim
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> DNM1 is DOUBLE PRECISION
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> d(N0-1).
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> \endverbatim
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>
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> \param[out] DNM2
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> \verbatim
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> DNM2 is DOUBLE PRECISION
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> d(N0-2).
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> \endverbatim
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>
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> \param[in] IEEE
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> \verbatim
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> IEEE is LOGICAL
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> Flag for IEEE or non IEEE arithmetic.
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> \endverbatim
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> \param[in] EPS
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> \verbatim
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> EPS is DOUBLE PRECISION
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> This is the value of epsilon used.
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> \endverbatim
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>
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Authors:
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========
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> \author Univ. of Tennessee
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> \author Univ. of California Berkeley
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> \author Univ. of Colorado Denver
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> \author NAG Ltd.
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> \date September 2012
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> \ingroup auxOTHERcomputational
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=====================================================================
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Subroutine */ int igraphdlasq5_(integer *i0, integer *n0, doublereal *z__,
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integer *pp, doublereal *tau, doublereal *sigma, doublereal *dmin__,
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doublereal *dmin1, doublereal *dmin2, doublereal *dn, doublereal *
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dnm1, doublereal *dnm2, logical *ieee, doublereal *eps)
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{
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/* System generated locals */
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integer i__1;
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doublereal d__1, d__2;
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/* Local variables */
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doublereal d__;
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integer j4, j4p2;
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doublereal emin, temp, dthresh;
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/* -- LAPACK computational routine (version 3.4.2) --
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-- LAPACK is a software package provided by Univ. of Tennessee, --
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-- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
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September 2012
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=====================================================================
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Parameter adjustments */
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--z__;
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/* Function Body */
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if (*n0 - *i0 - 1 <= 0) {
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return 0;
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}
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dthresh = *eps * (*sigma + *tau);
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if (*tau < dthresh * .5) {
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*tau = 0.;
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}
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if (*tau != 0.) {
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j4 = (*i0 << 2) + *pp - 3;
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emin = z__[j4 + 4];
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d__ = z__[j4] - *tau;
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*dmin__ = d__;
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*dmin1 = -z__[j4];
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if (*ieee) {
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/* Code for IEEE arithmetic. */
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if (*pp == 0) {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 2] = d__ + z__[j4 - 1];
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temp = z__[j4 + 1] / z__[j4 - 2];
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d__ = d__ * temp - *tau;
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*dmin__ = min(*dmin__,d__);
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z__[j4] = z__[j4 - 1] * temp;
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/* Computing MIN */
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d__1 = z__[j4];
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emin = min(d__1,emin);
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/* L10: */
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}
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} else {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 3] = d__ + z__[j4];
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temp = z__[j4 + 2] / z__[j4 - 3];
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d__ = d__ * temp - *tau;
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*dmin__ = min(*dmin__,d__);
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z__[j4 - 1] = z__[j4] * temp;
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/* Computing MIN */
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d__1 = z__[j4 - 1];
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emin = min(d__1,emin);
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/* L20: */
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}
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}
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/* Unroll last two steps. */
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*dnm2 = d__;
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*dmin2 = *dmin__;
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j4 = (*n0 - 2 << 2) - *pp;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm2 + z__[j4p2];
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dnm1 = z__[j4p2 + 2] * (*dnm2 / z__[j4 - 2]) - *tau;
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*dmin__ = min(*dmin__,*dnm1);
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*dmin1 = *dmin__;
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j4 += 4;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm1 + z__[j4p2];
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dn = z__[j4p2 + 2] * (*dnm1 / z__[j4 - 2]) - *tau;
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*dmin__ = min(*dmin__,*dn);
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} else {
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/* Code for non IEEE arithmetic. */
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if (*pp == 0) {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 2] = d__ + z__[j4 - 1];
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if (d__ < 0.) {
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return 0;
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} else {
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z__[j4] = z__[j4 + 1] * (z__[j4 - 1] / z__[j4 - 2]);
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d__ = z__[j4 + 1] * (d__ / z__[j4 - 2]) - *tau;
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}
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*dmin__ = min(*dmin__,d__);
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/* Computing MIN */
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d__1 = emin, d__2 = z__[j4];
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emin = min(d__1,d__2);
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/* L30: */
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}
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} else {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 3] = d__ + z__[j4];
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if (d__ < 0.) {
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return 0;
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} else {
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z__[j4 - 1] = z__[j4 + 2] * (z__[j4] / z__[j4 - 3]);
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d__ = z__[j4 + 2] * (d__ / z__[j4 - 3]) - *tau;
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}
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*dmin__ = min(*dmin__,d__);
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/* Computing MIN */
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d__1 = emin, d__2 = z__[j4 - 1];
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emin = min(d__1,d__2);
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/* L40: */
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}
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}
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/* Unroll last two steps. */
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*dnm2 = d__;
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*dmin2 = *dmin__;
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j4 = (*n0 - 2 << 2) - *pp;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm2 + z__[j4p2];
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if (*dnm2 < 0.) {
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return 0;
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} else {
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dnm1 = z__[j4p2 + 2] * (*dnm2 / z__[j4 - 2]) - *tau;
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}
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*dmin__ = min(*dmin__,*dnm1);
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*dmin1 = *dmin__;
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j4 += 4;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm1 + z__[j4p2];
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if (*dnm1 < 0.) {
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return 0;
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} else {
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dn = z__[j4p2 + 2] * (*dnm1 / z__[j4 - 2]) - *tau;
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}
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*dmin__ = min(*dmin__,*dn);
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}
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} else {
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/* This is the version that sets d's to zero if they are small enough */
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j4 = (*i0 << 2) + *pp - 3;
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emin = z__[j4 + 4];
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d__ = z__[j4] - *tau;
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*dmin__ = d__;
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*dmin1 = -z__[j4];
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if (*ieee) {
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/* Code for IEEE arithmetic. */
|
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|
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if (*pp == 0) {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 2] = d__ + z__[j4 - 1];
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temp = z__[j4 + 1] / z__[j4 - 2];
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d__ = d__ * temp - *tau;
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if (d__ < dthresh) {
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d__ = 0.;
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}
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*dmin__ = min(*dmin__,d__);
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z__[j4] = z__[j4 - 1] * temp;
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/* Computing MIN */
|
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d__1 = z__[j4];
|
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emin = min(d__1,emin);
|
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/* L50: */
|
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}
|
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} else {
|
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
|
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z__[j4 - 3] = d__ + z__[j4];
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temp = z__[j4 + 2] / z__[j4 - 3];
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d__ = d__ * temp - *tau;
|
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if (d__ < dthresh) {
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d__ = 0.;
|
||||
}
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*dmin__ = min(*dmin__,d__);
|
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z__[j4 - 1] = z__[j4] * temp;
|
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/* Computing MIN */
|
||||
d__1 = z__[j4 - 1];
|
||||
emin = min(d__1,emin);
|
||||
/* L60: */
|
||||
}
|
||||
}
|
||||
|
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/* Unroll last two steps. */
|
||||
|
||||
*dnm2 = d__;
|
||||
*dmin2 = *dmin__;
|
||||
j4 = (*n0 - 2 << 2) - *pp;
|
||||
j4p2 = j4 + (*pp << 1) - 1;
|
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z__[j4 - 2] = *dnm2 + z__[j4p2];
|
||||
z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
|
||||
*dnm1 = z__[j4p2 + 2] * (*dnm2 / z__[j4 - 2]) - *tau;
|
||||
*dmin__ = min(*dmin__,*dnm1);
|
||||
|
||||
*dmin1 = *dmin__;
|
||||
j4 += 4;
|
||||
j4p2 = j4 + (*pp << 1) - 1;
|
||||
z__[j4 - 2] = *dnm1 + z__[j4p2];
|
||||
z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
|
||||
*dn = z__[j4p2 + 2] * (*dnm1 / z__[j4 - 2]) - *tau;
|
||||
*dmin__ = min(*dmin__,*dn);
|
||||
|
||||
} else {
|
||||
|
||||
/* Code for non IEEE arithmetic. */
|
||||
|
||||
if (*pp == 0) {
|
||||
i__1 = *n0 - 3 << 2;
|
||||
for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
|
||||
z__[j4 - 2] = d__ + z__[j4 - 1];
|
||||
if (d__ < 0.) {
|
||||
return 0;
|
||||
} else {
|
||||
z__[j4] = z__[j4 + 1] * (z__[j4 - 1] / z__[j4 - 2]);
|
||||
d__ = z__[j4 + 1] * (d__ / z__[j4 - 2]) - *tau;
|
||||
}
|
||||
if (d__ < dthresh) {
|
||||
d__ = 0.;
|
||||
}
|
||||
*dmin__ = min(*dmin__,d__);
|
||||
/* Computing MIN */
|
||||
d__1 = emin, d__2 = z__[j4];
|
||||
emin = min(d__1,d__2);
|
||||
/* L70: */
|
||||
}
|
||||
} else {
|
||||
i__1 = *n0 - 3 << 2;
|
||||
for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
|
||||
z__[j4 - 3] = d__ + z__[j4];
|
||||
if (d__ < 0.) {
|
||||
return 0;
|
||||
} else {
|
||||
z__[j4 - 1] = z__[j4 + 2] * (z__[j4] / z__[j4 - 3]);
|
||||
d__ = z__[j4 + 2] * (d__ / z__[j4 - 3]) - *tau;
|
||||
}
|
||||
if (d__ < dthresh) {
|
||||
d__ = 0.;
|
||||
}
|
||||
*dmin__ = min(*dmin__,d__);
|
||||
/* Computing MIN */
|
||||
d__1 = emin, d__2 = z__[j4 - 1];
|
||||
emin = min(d__1,d__2);
|
||||
/* L80: */
|
||||
}
|
||||
}
|
||||
|
||||
/* Unroll last two steps. */
|
||||
|
||||
*dnm2 = d__;
|
||||
*dmin2 = *dmin__;
|
||||
j4 = (*n0 - 2 << 2) - *pp;
|
||||
j4p2 = j4 + (*pp << 1) - 1;
|
||||
z__[j4 - 2] = *dnm2 + z__[j4p2];
|
||||
if (*dnm2 < 0.) {
|
||||
return 0;
|
||||
} else {
|
||||
z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
|
||||
*dnm1 = z__[j4p2 + 2] * (*dnm2 / z__[j4 - 2]) - *tau;
|
||||
}
|
||||
*dmin__ = min(*dmin__,*dnm1);
|
||||
|
||||
*dmin1 = *dmin__;
|
||||
j4 += 4;
|
||||
j4p2 = j4 + (*pp << 1) - 1;
|
||||
z__[j4 - 2] = *dnm1 + z__[j4p2];
|
||||
if (*dnm1 < 0.) {
|
||||
return 0;
|
||||
} else {
|
||||
z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
|
||||
*dn = z__[j4p2 + 2] * (*dnm1 / z__[j4 - 2]) - *tau;
|
||||
}
|
||||
*dmin__ = min(*dmin__,*dn);
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
z__[j4 + 2] = *dn;
|
||||
z__[(*n0 << 2) - *pp] = emin;
|
||||
return 0;
|
||||
|
||||
/* End of DLASQ5 */
|
||||
|
||||
} /* igraphdlasq5_ */
|
||||
|
||||
Reference in New Issue
Block a user