ang2pix

Convert spherical coordinate location to HEALPix pixel number

Contents

Syntax

pix = ang2pix(nSide, v);
pix = ang2pix(nSide, v, nest);

Input Arguments

nSide      HEALPix resolution parameter
v          (theta, phi) pairs in radians as either [2,n] or as cellarray
           of [2,1]
nest       (optional) nested pixel number scheme (true | {false})

Return Arguments

pix             array of pix numbers:
               v on input     output
               iscell(v)      size(v) cell array of pixel numbers
               isnumeric(v)   size(v,1) numeric array of pixel numbers

Note that Matlab numbers pixels from 1

Example

vTheta = acos(2*rand(3,5)-1);
vPhi = 2*pi*rand(3,5);
vc = arrayfun(@(x,y)([x;y]),vTheta,vPhi,'UniformOutput',false);
va = reshape(cell2mat(vc),[2,3,5]);
nSide = 8;
size(vc)
size(va)
pix = ang2pix(nSide,vc)
pix = ang2pix(nSide,va)
ans =

     3     5


ans =

     2     3     5


pix =

   710   602   719   648   504
   527   167   488    78   610
   598   437   175   542   152


pix =

   710   602   719   648   504
   527   167   488    78   610
   598   437   175   542   152

See also

vec2pix, pix2ang, pix2vec

Requires

ring2nest

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