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