1 /* determine small t */
2 #include <math.h>
3 #include <projects.h>
4 
5 	double
pj_tsfn(double phi,double sinphi,double e)6 pj_tsfn(double phi, double sinphi, double e) {
7 	sinphi *= e;
8 	return (tan (.5 * (M_HALFPI - phi)) /
9 	   pow((1. - sinphi) / (1. + sinphi), .5 * e));
10 }
11