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author | Ulrich Drepper <drepper@redhat.com> | 2005-12-14 15:06:39 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 2005-12-14 15:06:39 +0000 |
commit | 9d13fb2413921c713f83efe331e8e4d219c62c6b (patch) | |
tree | 2d44d7ac45ab2d147eb8361bbff880c365aa8ad5 /math/s_cproj.c | |
parent | b6ab06cef4670e02756bcdd4d2c33a49369a4346 (diff) | |
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Moved to csu/errno-loc.c.
Diffstat (limited to 'math/s_cproj.c')
-rw-r--r-- | math/s_cproj.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/math/s_cproj.c b/math/s_cproj.c new file mode 100644 index 0000000000..8e7ca41df8 --- /dev/null +++ b/math/s_cproj.c @@ -0,0 +1,51 @@ +/* Compute projection of complex double value to Riemann sphere. + Copyright (C) 1997, 1999 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <complex.h> +#include <math.h> + + +__complex__ double +__cproj (__complex__ double x) +{ + __complex__ double res; + + if (isnan (__real__ x) && isnan (__imag__ x)) + return x; + else if (!isfinite (__real__ x) || !isfinite (__imag__ x)) + { + __real__ res = INFINITY; + __imag__ res = __copysign (0.0, __imag__ x); + } + else + { + double den = __real__ x * __real__ x + __imag__ x * __imag__ x + 1.0; + + __real__ res = (2.0 * __real__ x) / den; + __imag__ res = (2.0 * __imag__ x) / den; + } + + return res; +} +weak_alias (__cproj, cproj) +#ifdef NO_LONG_DOUBLE +strong_alias (__cproj, __cprojl) +weak_alias (__cproj, cprojl) +#endif |