Function healpixRingLat( k, index )

Description:
Returns the latitude of the approximate center of the tile with a given index in the HEALPix RING scheme.

Note: the index parameter is 0-based, unlike the table row index special token $index (a.k.a. $0), which is 1-based. So if the HEALpix index is implicitly determined by the table row, the value $index-1 should be used.

Parameters:
k (integer)
HEALPix order (0..29)
index (long integer)
healpix index
Return Value (floating point):
latitude in degrees
See Also:
HEALPix web site
Signature:
double healpixRingLat(int, long)