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Diffstat (limited to 'src/fmod.c')
| -rw-r--r-- | src/fmod.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/src/fmod.c b/src/fmod.c new file mode 100644 index 0000000..fe90e07 --- /dev/null +++ b/src/fmod.c @@ -0,0 +1,51 @@ +/*********************************************************** +Copyright 1991 by Stichting Mathematisch Centrum, Amsterdam, The +Netherlands. + + All Rights Reserved + +Permission to use, copy, modify, and distribute this software and its +documentation for any purpose and without fee is hereby granted, +provided that the above copyright notice appear in all copies and that +both that copyright notice and this permission notice appear in +supporting documentation, and that the names of Stichting Mathematisch +Centrum or CWI not be used in advertising or publicity pertaining to +distribution of the software without specific, written prior permission. + +STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO +THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND +FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE +FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT +OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +******************************************************************/ + +/* Portable fmod(x, y) implementation for systems that don't have it */ + +#include <math.h> +#include <errno.h> + +extern int errno; + +double +fmod(x, y) + double x, y; +{ + double i, f; + + if (y == 0.0) { + errno = EDOM; + return 0.0; + } + + /* return f such that x = i*y + f for some integer i + such that |f| < |y| and f has the same sign as x */ + + i = floor(x/y); + f = x - i*y; + if ((x < 0.0) != (y < 0.0)) + f = f-y; + return f; +} |
