uniq2nest


This F90 facility turns the Unique Identifier $u = p + 4 {N_{\rm side}}^2$, into the parameter ${N_{\rm side}}$ (a power of 2) and the pixel index p. 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 uniq2nest( puniq, nside, pnest )


ARGUMENTS

name kind in/out description
       
puniq I4B/I8B IN The HEALPix Unique pixel identifier. Must be $\ge 4$.
nside I4B OUT The HEALPix ${N_{\rm side}}$ parameter.
pnest I4B/I8B OUT (NESTED scheme) pixel identification number over the range {0, $12{N_{\rm side}}^2-1$}.


EXAMPLE:

use healpix_modules
integer(I4B) :: nside, pnest
call uniq2nest(4, nside, pnest)
print*,nside,pnest
returns
1 0
since the pixel with Unique ID number 4 is the first pixel (p=0) at ${N_{\rm side}}=$ 1.


RELATED ROUTINES

This section lists the routines related to uniq2nest

nest2uniq
Transforms Nside and Nested pixel number into Unique HEALPix pixel ID number
pix2xxx, ...
to turn NESTED pixel index into sky coordinates and back

Version 3.31, 2017-01-06