aasincos.c
731 Bytes
/* arc sin, cosine, tan2 and sqrt that will NOT fail */
#ifndef lint
static const char SCCSID[]="@(#)aasincos.c 4.6 93/12/12 GIE REL";
#endif
#include "projects.h"
#define ONE_TOL 1.00000000000001
#define TOL 0.000000001
#define ATOL 1e-50
double
aasin(double v) {
double av;
if ((av = fabs(v)) >= 1.) {
if (av > ONE_TOL)
pj_errno = -19;
return (v < 0. ? -HALFPI : HALFPI);
}
return asin(v);
}
double
aacos(double v) {
double av;
if ((av = fabs(v)) >= 1.) {
if (av > ONE_TOL)
pj_errno = -19;
return (v < 0. ? PI : 0.);
}
return acos(v);
}
double
asqrt(double v) { return ((v <= 0) ? 0. : sqrt(v)); }
double
aatan2(double n, double d) {
return ((fabs(n) < ATOL && fabs(d) < ATOL) ? 0. : atan2(n,d));
}