palDs2tp

Spherical to tangent plane projection

Projection of spherical coordinates onto tangent plane: " gnomonic" projection - " standard coordinates"

palDs2tp( double ra, double dec, double raz, double decz, double

*

xi, double

*

eta, int

*

j );

RA spherical coordinate of point to be projected (radians)

Dec spherical coordinate of point to be projected (radians)

RA spherical coordinate of tangent point (radians)

Dec spherical coordinate of tangent point (radians)

First rectangular coordinate on tangent plane (radians)

Second rectangular coordinate on tangent plane (radians)

status: 0 = OK, star on tangent plane 1 = error, star too far from axis 2 = error, antistar on tangent plane 3 = error, antistar too far from axis