nest2uniq

This F90 facility turns the parameter $N_{\mathrm{side}}$ (a power of 2) and the pixel index $p$ into the Unique ID number $u = p + 4 N_{\mathrm{side}}^2$. See ”The Unique Identifier scheme” section in ”HEALPix Introduction Document” for more details.

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

FORMAT

call nest2uniq( nside, pnest, puniq )

ARGUMENTS

name	kind	in/out	description
nside	I4B	IN	The HEALPix $N_{\mathrm{side}}$ parameter.
pnest	I4B/I8B	IN	(NESTED scheme) pixel identification number over the range {0, $12N_{\mathrm{side}}^2-1$}.
puniq	I4B/I8B	OUT	The HEALPix Unique pixel identifier.

EXAMPLE:

use healpix_modules
integer(I4B) :: puniq
call nest2uniq(1, 0, puniq)
print*,puniq

returns
4
since the first pixel ($p=0$) at $N_{\mathrm{side}}=$ 1 is the pixel with Unique ID number 4.

RELATED ROUTINES

This section lists the routines related to nest2uniq

uniq2nest

] Transforms Unique HEALPix pixel ID number into Nside and Nested pixel number

pix2xxx, ...

to turn NESTED pixel index into sky coordinates and back