diff options
Diffstat (limited to 'gsl-1.9/cblas/source_rotg.h')
-rw-r--r-- | gsl-1.9/cblas/source_rotg.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/gsl-1.9/cblas/source_rotg.h b/gsl-1.9/cblas/source_rotg.h new file mode 100644 index 0000000..24589e2 --- /dev/null +++ b/gsl-1.9/cblas/source_rotg.h @@ -0,0 +1,46 @@ +/* blas/source_rotg.h + * + * Copyright (C) 1996, 1997, 1998, 1999, 2000 Gerard Jungman + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +{ + const BASE roe = (fabs(*a) > fabs(*b) ? *a : *b); + const BASE scale = fabs(*a) + fabs(*b); + BASE r, z; + + if (scale != 0.0) { + const BASE aos = *a / scale; + const BASE bos = *b / scale; + r = scale * sqrt(aos * aos + bos * bos); + r = GSL_SIGN(roe) * r; + *c = *a / r; + *s = *b / r; + z = 1.0; + if (fabs(*a) > fabs(*b)) + z = *s; + if (fabs(*b) >= fabs(*a) && *c != 0.0) + z = 1.0 / (*c); + } else { + *c = 1.0; + *s = 0.0; + r = 0.0; + z = 0.0; + } + + *a = r; + *b = z; +} |