fits2cl*

This routine reads a power spectrum or beam window function from a FITS ASCII or binary table. The routine can read temperature coefficients $C_\ell^{TT}$ or both temperature and polarisation coefficients $C_\ell^{TT}$, $C_\ell^{EE}$, $C_\ell^{BB}$, $C_\ell^{TE}$ (and $C_\ell^{TB}$, $C_\ell^{EB}$, $C_\ell^{ET}$, $C_\ell^{BT}$, $C_\ell^{BE}$ when applicable). If the keyword PDMTYPE is found in the header, fits2cl assumes the table to be in the special format used by Planck and will ignore the first data column. If the input FITS file contains several extensions or HDUs, the one to be read can be specified thanks to the CFITSIO Extended File Name Syntax, using its number (eg, file.fits[2] or file.fits+2) or its EXTNAME value (eg. file.fits[beam_100x100]). By default, only the first valid extension will be read.

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

FORMAT

call fits2cl*( filename, clin, lmax, ncl, header, [units] )

ARGUMENTS

name & dimensionality	kind	in/out	description
filename(LEN=filenamelen)	CHR	IN	the FITS file containing the power spectrum.
lmax	I4B	IN	Maximum $\ell$ value to be read.
ncl	I4B	IN	1 for temperature coeffecients only, 4 for polarisation.
clin(0:lmax,1:ncl)	SP/ DP	OUT	the power spectrum read from the file.
header(LEN=80) (1:)	CHR	OUT	the header read from the FITS-file.
units(LEN=80) (1:)	CHR	OUT	the column units read from the FITS-file.

EXAMPLE:

use healpix_modules
real(SP), allocatable, dimension(:,:) :: cl
character(len=80), dimension(1:300) :: header
character(len=80), dimension(1:100) :: units
integer(I4B) :: lmax, ncl, np
character(len=filenamelen) :: fitsfile='cl.fits'
np = getsize_fits(fitsfile, nmaps=ncl, mlpol=lmax)
allocate(cl(0:lmax, 1:ncl))
call fits2cl(fitsfile, cl, lmax, ncl, header, units)

Reads a power spectrum from the FITS file `cl.fits' and stores the result in cl(0:lmax,1:ncl) which are the ncl $C_\ell$ coefficients up to $\ell=$lmax. The FITS header is returned in header, the column units in units.

MODULES & ROUTINES

This section lists the modules and routines used by fits2cl*.

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 fits2cl*

create_alm

Routine to create $a_{\ell m}$ values from an input power spectrum.

write_asctab

Routine to create an ascii FITS file containing a power spectrum.

getsize_fits

Routine to parse FITS file header, and determine the data storage features.

getnumext_fits

Routine to determine number of extensions of a FITS file.