xref: /plan9/sys/src/cmd/map/libmap/ccubrt.c (revision 59cc4ca53493a3c6d2349fe2b7f7c40f7dce7294)
1 #include <u.h>
2 #include <libc.h>
3 #include "map.h"
4 
5 void
ccubrt(double zr,double zi,double * wr,double * wi)6 ccubrt(double zr, double zi, double *wr, double *wi)
7 {
8 	double r, theta;
9 	theta = atan2(zi,zr);
10 	r = cubrt(hypot(zr,zi));
11 	*wr = r*cos(theta/3);
12 	*wi = r*sin(theta/3);
13 }
14