diff options
Diffstat (limited to 'lib/libF77/pow_di.c')
-rw-r--r-- | lib/libF77/pow_di.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/lib/libF77/pow_di.c b/lib/libF77/pow_di.c new file mode 100644 index 0000000..7af69a7 --- /dev/null +++ b/lib/libF77/pow_di.c @@ -0,0 +1,34 @@ +#include "f2c.h" + +#ifdef KR_headers +double pow_di(ap, bp) doublereal *ap; integer *bp; +#else +double pow_di(doublereal *ap, integer *bp) +#endif +{ +double pow, x; +integer n; + +pow = 1; +x = *ap; +n = *bp; + +if(n != 0) + { + if(n < 0) + { + n = -n; + x = 1/x; + } + for( ; ; ) + { + if(n & 01) + pow *= x; + if(n >>= 1) + x *= x; + else + break; + } + } +return(pow); +} |