convert_oldhpx2cmbfast

This IDL facility provides a means to change the normalization of polarization power spectra in a FITS file from Healpix 1.1 convention to Healpix 1.2 (which is the same as CMBFAST).

Location in HEALPix directory tree: src/idl/fits/convert_oldhpx2cmbfast.pro 

FORMAT

IDL> CONVERT_OLDHPX2CMBFAST, file_in, [file_out, NO_RENORM=]

QUALIFIERS

file_in

String containing the name of the FITS file with the power spectra to be read.

file_out

(OPTIONAL) String containing the name of the file to be written after renormalization. If absent, file_in will be used for output

KEYWORDS

NO_RENORM=

if set, the renormalization is not done. but the keyword POLNORM = CMBFAST is added to the FITS header (useful if the FITS file is already in CMBFAST format).

DESCRIPTION

convert_oldhpx2cmbfast does the conversion from the polarization normalisation used in HEALPix 1.1 to the one used in HEALPix 1.2 (see the

Healpix primer document). A keyword POLNORM = CMBFAST is added to the header to keep track of which files have been renormalized. If this keyword is not present in the input FITS file, synfast will issue a warning when simulating a polarization map from that power spectrum, but no attempt to renormalize the power spectra will be made.

RELATED ROUTINES

This section lists the routines related to convert_oldhpx2cmbfast

idl

version 6.4 or more is necessary to run convert_oldhpx2cmbfast.

cl2fits

provides the a routine to write a power spectrum to a FITS file.

fits2cl

provides the complimentary routine to read in a power spectrum from a FITS file.

synfast

utilises the output file generated by convert_oldhpx2cmbfast.

EXAMPLE:

convert_oldhpx2cmbfast, 'cl_flat.fits'

convert_oldhpx2cmbfast will renormalize the polarization power spectra read from 'cl_flat.fits', and write them in the same file.