# ring2z

Find HEALPix ring number corresponding to a given z coordinate

## Contents

- Syntax
- Input Arguments
- Return Arguments
- Example
- See also

## Syntax

    z = ring2z(nSide,nRing)

## Input Arguments

    nSide    HEALPix resolution parameter
    nRing    numeric array of ring numbers (in range [1,4*nSide-1])

## Return Arguments

    z        size(nRing) numeric array of pixel center z coordinates

## Example

    nRing = reshape(1:15,3,5)
    z = ring2z(4,nRing)

    nRing =

         1     4     7    10    13
         2     5     8    11    14
         3     6     9    12    15

    z =

        0.9792    0.6667    0.1667   -0.3333   -0.8125
        0.9167    0.5000         0   -0.5000   -0.9167
        0.8125    0.3333   -0.1667   -0.6667   -0.9792

## See also

z2ring

Copyright 2010-2011 Lee Samuel Finn. Terms of Use.