nside2npix

Function to provide the number of pixels $N_{\mathrm{pix}}$ over the full sky corresponding to resolution parameter $N_{\mathrm{side}}$.

Location in HEALPix directory tree: src/f90/mod/pix_tools.F90 

FORMAT

var=nside2npix( nside )

ARGUMENTS

name & dimensionality	kind	in/out	description
nside	I4B	IN	the $N_{\mathrm{side}}$ parameter of the map.
var	I8B	OUT	the number of pixels $N_{\mathrm{pix}}$ of the map. If $N_{\mathrm{side}}$ is valid (a power of 2 in $\{1,\ldots,2^{28}=268435456\}$), $N_{\mathrm{pix}}=12N_{\mathrm{side}}^2$ is returned; if not, an error message is issued and -1 is returned.

EXAMPLE:

use healpix_modules
integer(I8B) :: npix
npix= nside2npix(256)

Returns the number of HEALPix pixels (786432) for the resolution parameter 256.

RELATED ROUTINES

This section lists the routines related to nside2npix

npix2nside

returns resolution parameter corresponding to the number of pixels.