2 * This file is part of the GROMACS molecular simulation package.
4 * Copyright (c) 2012,2013, by the GROMACS development team, led by
5 * David van der Spoel, Berk Hess, Erik Lindahl, and including many
6 * others, as listed in the AUTHORS file in the top-level source
7 * directory and at http://www.gromacs.org.
9 * GROMACS is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public License
11 * as published by the Free Software Foundation; either version 2.1
12 * of the License, or (at your option) any later version.
14 * GROMACS is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with GROMACS; if not, see
21 * http://www.gnu.org/licenses, or write to the Free Software Foundation,
22 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 * If you want to redistribute modifications to GROMACS, please
25 * consider that scientific software is very special. Version
26 * control is crucial - bugs must be traceable. We will be happy to
27 * consider code for inclusion in the official distribution, but
28 * derived work must not be called official GROMACS. Details are found
29 * in the README & COPYING files - if they are missing, get the
30 * official version at http://www.gromacs.org.
32 * To help us fund GROMACS development, we humbly ask that you cite
33 * the research papers on the package. Check out http://www.gromacs.org.
36 #include "gmx_lapack.h"
37 #include "lapack_limits.h"
39 #include <types/simple.h>
42 F77_FUNC(dlasv2,DLASV2)(double *f,
54 double a, d__, l, m, r__, s, t, fa, ga, ha, ft, gt, ht, mm, tt,
81 if (fabs(ga)<GMX_DOUBLE_MIN) {
93 if (fa / ga < GMX_DOUBLE_EPS) {
98 *ssmin = fa / (ga / ha);
100 *ssmin = fa / ga * ha;
111 if ( fabs( fa - d__ )<GMX_DOUBLE_EPS*fabs( fa + d__ )) {
124 if ( fabs(l)<GMX_DOUBLE_MIN) {
127 r__ = sqrt(l * l + mm);
133 if ( fabs(mm)<GMX_DOUBLE_MIN) {
135 if (fabs(l)<GMX_DOUBLE_MIN) {
136 t = ( (ft>0) ? 2.0 : -2.0) * ( (gt>0) ? 1.0 : -1.0);
138 t = gt / ( (ft>0) ? d__ : d__) + m / t;
141 t = (m / (s + t) + m / (r__ + l)) * (a + 1.);
143 l = sqrt(t * t + 4.);
146 clt = (crt + srt * m) / a;
147 slt = ht / ft * srt / a;
163 tsign = ( (*csr>0) ? 1.0 : -1.0) * ( (*csl>0) ? 1.0 : -1.0) * ( (*f>0) ? 1.0 : -1.0);
166 tsign = ( (*snr>0) ? 1.0 : -1.0) * ( (*csl>0) ? 1.0 : -1.0) * ( (*g>0) ? 1.0 : -1.0);
169 tsign = ( (*snr>0) ? 1.0 : -1.0) * ( (*snl>0) ? 1.0 : -1.0) * ( (*h__>0) ? 1.0 : -1.0);
173 d__1 = tsign * ( (*f>0) ? 1.0 : -1.0) * ( (*h__>0) ? 1.0 : -1.0);