getsize_fits

This routine reads the number of maps and/or the pixel ordering of a FITS file containing a HEALPix map.

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

FORMAT

var=getsize_fits( filename[, nmaps, ordering, obs_npix, nside, mlpol, type, polarisation, fwhm_arcmin, beam_leg, coordsys, polcconv, extno] )

Arguments appearing in italic are optional.

ARGUMENTS

name & dim.	kind	in/out	description
var	I8B	OUT	number of pixels or time samples in the chosen extension of the FITS file
filename(LEN=*)	CHR	IN	filename of the FITS-file containing HEALPix map(s).

name & dim.	kind	in/out	description
nmaps (OPTIONAL)	I4B	OUT	number of maps in the extension.
ordering (OPTIONAL)	I4B	OUT	pixel ordering, 0=unknown, 1=RING, 2=NESTED
obs_npix (OPTIONAL)	I4B	OUT	number of non blanck pixels. It is set to -1 if it can not be determined from header information alone
nside (OPTIONAL)	I4B	OUT	Healpix resolution parameter Nside. Returns a negative value if not found.
mlpol (OPTIONAL)	I4B	OUT	maximum multipole used to generate the map (for simulated map). Returns a negative value if not found.
type (OPTIONAL)	I4B	OUT	Healpix/FITS file type $<$0 : file not found, or not valid 0 : image only fits file, deprecated Healpix format (var = 12 * nside * nside) 1 : ascii table, generally used for C(l) storage 2 : binary table : with implicit pixel indexing (full sky) (var = 12 * nside * nside) 3 : binary table : with explicit pixel indexing (generally cut sky) (var $\le$ 12 * nside * nside) 999 : unable to determine the type
polarisation (OPTIONAL)	I4B	OUT	presence of polarisation data in the file $<$0 : can not find out 0 : no polarisation 1 : contains polarisation (Q,U or G,C)
fwhm_arcmin (OPTIONAL)	DP	OUT	returns the beam FWHM read from FITS header, translated from Deg (hopefully) to arcmin. Returns a negative value if not found.
beam_leg(LEN=*) (OPTIONAL)	CHR	OUT	filename of beam or filtering window function applied to data (FITS keyword BEAM_LEG). Returns a empty string if not found.
coordsys(LEN=20) (OPTIONAL)	CHR	OUT	string describing the pixelation astrophysical coordinates. 'G' = Galactic, 'E' = ecliptic, 'C' = celestial = equatorial. Returns a empty string if not found.
polcconv (OPTIONAL)	I4B	OUT	polarisation coordinate convention (see Healpix primer for details) 0=unknown, 1=COSMO, 2=IAU, 3=neither COSMO nor IAU
extno (OPTIONAL)	I4B	IN	extension number (0 based) for which information is provided. Default = 0 (first extension).

EXAMPLE:

npix= getsize_fits('map.fits', nmaps=nmaps, ordering=ordering, obs_npix=obs_npix, nside=nside, mlpol=mlpol, type=type, polarisation=polarisation)

Returns 1 or 3 in nmaps, dependent on wether 'map.fits' contain only temperature or both temperature and polarisation maps. The pixel ordering number is found by reading the keyword ORDERING in the FITS file. If this keyword does not exist, 0 is returned.

MODULES & ROUTINES

This section lists the modules and routines used by getsize_fits.

fitstools

module, containing:

printerror

routine for printing FITS error messages.

cfitsio

library for FITS file handling.

RELATED ROUTINES

This section lists the routines related to getsize_fits

getnumext_fits

routine returning the number of extension in a FITS file

input_map

routine to read a HEALPix FITS file