queryDisc
Find all pixels whose centers are within a specified disc
Contents
Syntax
pix = queryDisc(nSide,c0,r,'Param1',Value1,...)
Input Arguments
nSide HEALPix resolution parameter c0 disc center. May be specified as a pixel number, spherical coordinate location [theta, phi] in rads, or as a cartesian unit vector [x;y;z]. r disc radius (radians)
Param Value 'nest' pixels are returned using nested indexing (true | {false})
Return Arguments
pix list of pixels in disc
Example
nSide=32; % Pixels within pi/10 radians of north pole pix = queryDisc(nSide,[0;0;1],pi/10); numel(pix) nSide2nPix(nSide)*((pi/10)/(4*pi)) % Pixels within pi/10 radians of south pole pix = queryDisc(nSide,[0;0;-1],pi/10); numel(pix) % Pixels within pi/10 radians of 0 long, lat pix = queryDisc(nSide,[1;0;0],pi/10); numel(pix)
ans = 312 ans = 307.2000 ans = 312 ans = 302
See also
queryPolygon, queryStrip, queryTriangle
Requires
pix2vec, ang2vec, angDist
Copyright 2010-2011 Lee Samuel Finn. Terms of Use.