medfiltmap*

This routine performs the median filtering of a HEALPix full sky map for a given neighborhood radius

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

FORMAT

call medfiltmap*( in_map, radius, med_map[, nest, fmissval, fill_holes] )

ARGUMENTS

name & dimensionality	kind	in/out	description
in_map(0:npix-1)	SP/ DP	IN	Full sky HEALPix map to filter. npix should be valid HEALPix pixel number.
radius	DP	IN	Radius in RADIANS of the disk on which the median is computed.
med_map(0:npix-1)	SP/ DP	OUT	Median filtered map: each pixel is the median of the input map valid neighboring pixels contained within a distance radius
nest OPTIONAL	I4B	IN	set to 1 if the map ordering is NESTED, set to 0 if it is RING.
fmissval OPTIONAL	SP/ DP	IN	sentinel value given to missing or non-valid pixels. Default: HPX_SBADVAL or HPX_DBADVAL $= -1.6375\ 10^{30}$
fill_holes OPTIONAL	LGT	IN	if set to .true. will replace non-valid pixels by median of neighbors; if set to .false. will leave non-valid pixels unchanged. Default: .false.

EXAMPLE:

use healpix_types
use pix_tools
...
call medfiltmap(map, 0.5*DEG2RAD, med)

Output in med the median filter of map, using a filter radius of 0.5 Deg

MODULES & ROUTINES

This section lists the modules and routines used by medfiltmap*.

statistics

module, containing:

median

routine to compute the median of a data set

pix_tools

module, containing:

pix2vec_ring, pix2vec_nest

routines to find the location of a pixel on the sky

query_disc

routine to find pixels lying within a radius of a given point