Function healpixNestLon( k, index )

Description:
Returns the longitude of the approximate center of the tile with a given index in the HEALPix NEST scheme.
Parameters:
k (integer)
HEALPix order (0..29)
index (long integer)
healpix index
Return Value (floating point):
longitude in degrees
Signature:
double healpixNestLon(int, long)