nside2npix
nside2npix checks that the given Nside is valid (power of 2 in {1,..., 8192}) and then computes the corresponding number of pixels Npix = 12Nside2.
Npix = nside2npix(256, ERROR=error) |
Npix will be 786432 the number of pixels over the full sky for the HEALPix resolution parameter 256 and error will be 0
Npix = nside2npix(248, ERROR=error) |
Npix will be -1 and error: 1, because 248 is not a valid value for a HEALPix resolution parameter
Eric Hivon 2003-02-07