1 files changed, 36 insertions, 0 deletions
diff --git a/src/aasincos.c b/src/aasincos.c
new file mode 100644
index 00000000..27aab829
--- /dev/null
+++ b/src/aasincos.c
@@ -0,0 +1,36 @@
+/* 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));
+}