add function that converts degrees to radians

src/reihen.c

@@ -6,6 +6,8 @@
 #include "exponent.h"
 #include "logarithmus.h"
 
+#define PI pi(1e-8)
+
 unsigned long long fac(int x){
     unsigned long long prod = 1;
     if(x==0) return 1;
@@ -30,6 +32,15 @@ double euler(){
     return exponential(1);
 }
 
+double squashDegreesTo360(double x){
+    int multiple = x / 360;
+    return x - (360*multiple);
+}
+
+double radians(double d){
+    return d / PI * 180;
+}
+
 double pi(double eps){
     double a = 1, b = 1/powerD(0.5, 2), t = 0.25, p = 1;
     double aNew, piold, pi = 1;