size_holes_nest


For a input binary mask in NESTED ordering, size_holes_nest identifies the pixels located on the inner boundary of invalid regions

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


FORMAT

call size_holes_nest( nside, mask, nholes, nph, [tags, sizeholes, listpix] )

Arguments appearing in italic are optional.


ARGUMENTS

name & dim. kind in/out description
       
nside I4B IN The Nside value of the input mask.
mask(0:Npix-1) I4B IN Input binary NESTED-ordered mask. Npix = 12*nside*nside
nholes I4B OUT Number of holes found
nph I4B OUT Number of pixels in holes
tags(0:Npix-1) (OPTIONAL) I4B OUT Pointer allocated by size_holes_nest, containing a sky map in which invalid pixels belonging to the largest hole have value -1, those belonging to the second largest hole have value -2, and so on, while valid pixels keep value +1.
sizeholes(0:nholes-1) I4B OUT Pointer allocated by size_holes_nest, containing on output the respective size of each hole (in decreasing order). Eg, sizeholes(0) is the number of pixels in the largest hole (taking value -1 in tags).
listpix(0:nholes+nph) I4B OUT Pointer allocated by size_holes_nest, containing on output the indexed list of pixels in each hole. Pixels located in the first (and largest) hole are given by listpix(listpix(0):listpix(1)-1)


EXAMPLE:

use healpix_types
use healpix_modules
...
call size_holes_nest(nside, mask, nholes, nph)
???


MODULES & ROUTINES

This section lists the modules and routines used by size_holes_nest.

mask_tools
mask processing module (see related routines below)


RELATED ROUTINES

This section lists the routines related to size_holes_nest

dist2holes_nest
angular distance to closest invalid pixel of the given mask
fill_holes_nest
turn to valid all pixels located in 'holes' containing fewer pixels than the given threshold
maskborder_nest
identify inner boundary pixels of 'holes' for given mask
size_holes_nest
returns size (in pixels) of holes found in input mask

Version 3.31, 2017-01-06