protected PJ_stere setup()
{ // general initialization
double t = Math.Abs(phi0);
if (Math.Abs(t - Proj.HALFPI) < EPS10)
{
mode = phi0 < 0.0?stere_mode.S_POLE:stere_mode.N_POLE;
}
else
{
mode = t > EPS10?stere_mode.OBLIQ:stere_mode.EQUIT;
}
phits = Math.Abs(phits);
if (es != 0)
{
switch (mode)
{
case stere_mode.N_POLE:
case stere_mode.S_POLE:
if (Math.Abs(phits - Proj.HALFPI) < EPS10)
{
akm1 = 2.0 * k0 / Math.Sqrt(Math.Pow(1 + e, 1 + e) * Math.Pow(1 - e, 1 - e));
}
else
{
t = Math.Sin(phits);
akm1 = Math.Cos(phits) / Proj.pj_tsfn(phits, t, e);
t *= e;
akm1 /= Math.Sqrt(1.0 - t * t);
}
break;
case stere_mode.EQUIT:
case stere_mode.OBLIQ:
t = Math.Sin(phi0);
double X = 2.0 * Math.Atan(ssfn_(phi0, t, e)) - Proj.HALFPI;
t *= e;
akm1 = 2.0 * k0 * Math.Cos(phi0) / Math.Sqrt(1.0 - t * t);
sinX1 = Math.Sin(X);
cosX1 = Math.Cos(X);
break;
}
inv = e_inverse;
fwd = e_forward;
}
else
{
switch (mode)
{
case stere_mode.OBLIQ:
sinX1 = Math.Sin(phi0);
cosX1 = Math.Cos(phi0);
goto case stere_mode.EQUIT;
case stere_mode.EQUIT:
akm1 = 2.0 * k0;
break;
case stere_mode.S_POLE:
case stere_mode.N_POLE:
akm1 = Math.Abs(phits - Proj.HALFPI) >= EPS10?Math.Cos(phits) / Math.Tan(Proj.FORTPI - 0.5 * phits) : 2.0 * k0;
break;
}
inv = s_inverse;
fwd = s_forward;
}
return(this);
}
protected PJ_stere setup()
{
// general initialization
double t=Math.Abs(phi0);
if(Math.Abs(t-Proj.HALFPI)<EPS10) mode=phi0<0.0?stere_mode.S_POLE:stere_mode.N_POLE;
else mode=t>EPS10?stere_mode.OBLIQ:stere_mode.EQUIT;
phits=Math.Abs(phits);
if(es!=0)
{
switch(mode)
{
case stere_mode.N_POLE:
case stere_mode.S_POLE:
if(Math.Abs(phits-Proj.HALFPI)<EPS10) akm1=2.0*k0/Math.Sqrt(Math.Pow(1+e, 1+e)*Math.Pow(1-e, 1-e));
else
{
t=Math.Sin(phits);
akm1=Math.Cos(phits)/Proj.pj_tsfn(phits, t, e);
t*=e;
akm1/=Math.Sqrt(1.0-t*t);
}
break;
case stere_mode.EQUIT:
case stere_mode.OBLIQ:
t=Math.Sin(phi0);
double X=2.0*Math.Atan(ssfn_(phi0, t, e))-Proj.HALFPI;
t*=e;
akm1=2.0*k0*Math.Cos(phi0)/Math.Sqrt(1.0-t*t);
sinX1=Math.Sin(X);
cosX1=Math.Cos(X);
break;
}
inv=e_inverse;
fwd=e_forward;
}
else
{
switch(mode)
{
case stere_mode.OBLIQ:
sinX1=Math.Sin(phi0);
cosX1=Math.Cos(phi0);
goto case stere_mode.EQUIT;
case stere_mode.EQUIT:
akm1=2.0*k0;
break;
case stere_mode.S_POLE:
case stere_mode.N_POLE:
akm1=Math.Abs(phits-Proj.HALFPI)>=EPS10?Math.Cos(phits)/Math.Tan(Proj.FORTPI-0.5*phits):2.0*k0;
break;
}
inv=s_inverse;
fwd=s_forward;
}
return this;
}
