write_minimal_header

This routine writes the baseline FITS header for the most common HEALPix data sets: (cut sky or full sky) map, $C(\ell)$ power spectra and $a_{\ell m}$ coefficients.

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

FORMAT

call write_minimal_header( header, dtype, [append, nside, order, ordering, coordsys, creator, version, randseed, beam_leg, fwhm_degree, units, nlmax, polar, nmmax, bcross, deriv, asym_cl] )

Arguments appearing in italic are optional.

ARGUMENTS

name & dimensionality	kind	in/out	description
header(LEN=80) DIMENSION(:)	CHR	INOUT	The FITS header to fill in.
dtype(LEN=*)	CHR	IN	data to be put in the FITS file, must be one of 'ALM', 'CL', 'MAP', 'CUTMAP' (case un-sensitive).

name & dimensionality	kind	in/out	description
append	LGT	IN	if set to TRUE, the keywords will be appended to the content of header instead of written from scrath
nside	I4B	IN	map resolution parameter; required for dtype='MAP' and dtype='CUTMAP'
order	I4B	IN	map ordering, either 1 (=ring) or 2 (=nested); see ordering
ordering(LEN=*)	CHR	IN	map ordering, either 'RING' or 'NESTED' (case un-sensitive); either order or ordering is required for dtype='MAP' and dtype='CUTMAP'
coordsys(LEN=*)	CHR	IN	map coordinate system; Valid choices are 'G' = Galactic, 'E' = Ecliptic, 'C'/'Q' = Celestial = eQuatorial
creator(LEN=*)	CHR	IN	name of software generating the data set
version(LEN=*)	CHR	IN	version of creator software
randseed	I4B	IN	random number generator seed used to generate the data
beam_leg(LEN=*)	CHR	IN	File containing Legendre transform of symmetric beam
fwhm_degree	DP	IN	FWHM in degrees of gaussian symmetric beam (FITS keyword: FWHM)
units(LEN=*)	CHR	IN	physical units of the data set (FITS keyword: TUNIT*)
nlmax	I4B	IN	maximum multipole order $l$ of the data set (FITS keyword: MAX-LPOL)
polar	LGT	IN	if set to .TRUE., the file to be written contains polarized data
nmmax	I4B	IN	maximum degree $m$ of data set (FITS keyword: MAX-MPOL)
bcross	LGT	IN	if set to .TRUE., the magnetic cross terms power spectra (TB and EB) are included; only applies to dtype='CL'
deriv	I4B	IN	order of derivatives to included in FITS file (0, 1 or 2); only applies to dtype='MAP'
asym_cl	LGT	IN	if set to .TRUE., the asymmetric power spectra (ET, BT and BE on top of TE, TB and EB) are included; only applies to dtype='CL'

EXAMPLE:

use healpix_types
use head_fits
character(len=80), dimension(1:60) :: header
call write_minimal_header(header, 'MAP', nside=256, ordering='Nested')
call add_card(header, 'HISTORY', 'Dummy map')

Writes in header a HEALPix compliant FITS header for a $N_{\mathrm{side}}=256$ map with NESTED ordering. Further HISTORY information is added with add_card

MODULES & ROUTINES

This section lists the modules and routines used by write_minimal_header.

write_hl

more general routine for adding a keyword to a header.

cfitsio

library for FITS file handling.

RELATED ROUTINES

This section lists the routines related to write_minimal_header

add_card

general purpose routine to write/edit an arbitrary keyword into a FITS file header.

get_card

general purpose routine to read any keywords from a header in a FITS file.

del_card

routine to discard a keyword from a FITS header

read_par, number_of_alms

routines to read specific keywords from a header in a FITS file.

getsize_fits

function returning the size of the data set in a fits file and reading some other useful FITS keywords

merge_headers

routine to merge two FITS headers