write_fits_cut4

This routine writes a cut sky HEALPix map into a FITS file. The format used for the FITS file follows the one used for Boomerang98 and is adapted from COBE/DMR. This routine can be used to store polarized maps, where the information relative to the Stokes parameters I, Q and U are placed in extension 0, 1 and 2 respectively by successive invocation of the routine.

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

FORMAT

call write_fits_cut4( filename, np, pixel, signal, n_obs, serror[, header, coord, nside, order, units, extno, polarisation] )

Arguments appearing in italic are optional.

ARGUMENTS

name&dimensionality	kind	in/out	description
filename(LEN=filenamelen)	CHR	IN	FITS file into which the cut sky map will be written
np	I4B	IN	number of pixels to be written in the file
pixel(0:np-1)	I4B	IN	index of observed (or valid) pixels
signal(0:np-1)	SP	IN	value of signal in each observed pixel
n_obs(0:np-1)	I4B	IN	number of observation per pixel
serror(0:np-1)	SP	IN	rms of signal in pixel, for white noise, this is $\propto 1/\sqrt{{\rm n\_obs}}$.
header(LEN=80)(1:) (OPTIONAL)	CHR	IN	FITS extension header to be included in the FITS file
coord(LEN=1)	CHR	IN	astrophysical coordinates ('C' or 'Q' Celestial/eQuatorial, 'G' for Galactic, 'E' for Ecliptic)
nside	I4B	IN	HEALPix resolution parameter of data set
order	I4B	IN	HEALPix ordering scheme, 1: RING, 2: NESTED
units(LEN=20)	CHR	IN	maps units (applies only to Signal and Serror)
extno	I4B	IN	(0 based) extension number in which to write data. default:0. If set to 0 (or not set) a new file is written from scratch. If set to a value larger than 1, the corresponding extension is added or updated, as long as all previous extensions already exist. All extensions of the same file should use the same Nside, Order and Coord
polarisaton	I4B	IN	if set to a non zero value, specifies that file will contain the I, Q and U polarisation Stokes parameter in extensions 0, 1 and 2 respectively, and sets the FITS header keywords accordingly. If not set, the keywords found in header will prevail.
			Note: the information relative to Nside, Order and Coord has to be given, either thru these keyword or via the FITS Header.

MODULES & ROUTINES

This section lists the modules and routines used by write_fits_cut4.

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 write_fits_cut4

anafast

executable that reads a HEALPix map and analyses it.

synfast

executable that generate full sky HEALPix maps

getsize_fits

routine to know the size of a FITS file and its type (eg, full sky vs cut sky)

input_map

all purpose routine to input a map of any kind from a FITS file

output_map

subroutine to write a FITS file from a HEALPix map

read_fits_cut4

subroutine to read a HEALPix cut sky map from a FITS file

write_minimal_header

routine to write minimal FITS header