Exemplo n.º 1
0
        public override PJ Init()
        {
            phi1 = Math.Abs(Proj.pj_param_r(ctx, parameters, "lat_ts"));
            mode = phi1 > EPS;

            if (mode)
            {
                fxb = 0.5 * Math.Sin(phi1);
                fxa = 0.5 / fxb;
            }

            es  = 0.0;
            fwd = s_forward;

            return(this);
        }
Exemplo n.º 2
0
        public double proj_inv_mdist(projCtx ctx, double dist)
        {
            double k   = 1.0 / (1.0 - es);
            int    i   = MAX_ITER_mdist;
            double phi = dist;

            while (i-- > 0)
            {
                double s = Math.Sin(phi);
                double t = 1.0 - es * s * s;
                phi -= t = (proj_mdist(phi, s, Math.Cos(phi)) - dist) * (t * Math.Sqrt(t)) * k;
                if (Math.Abs(t) < TOL14)
                {
                    return(phi);                                  // that is no change
                }
            }

            // convergence failed
            Proj.pj_ctx_set_errno(ctx, -17);
            return(phi);
        }