Application: gvSIG desktop

/* determine small q */

#ifndef lint

static const char SCCSID[]="@(#)pj_qsfn.c        4.3        93/06/12        GIE        REL";

#endif

#include <math.h>

#include <projects.h>

# define EPSILON 1.0e-7

        double

pj_qsfn(double sinphi, double e, double one_es) {

        double con;

        if (e >= EPSILON) {

                con = e * sinphi;

                return (one_es * (sinphi / (1. - con * con) -

                   (.5 / e) * log ((1. - con) / (1. + con))));

        } else

                return (sinphi + sinphi);

}