create_alm
call create_alm( nsmax, nlmax, nmmax, polar, filename, iseed, fwhm_arcmin, alm_TGC, header [, windowfile, units, beam_file] )
name&dimensionality | kind | in/out | description |
---|---|---|---|
nsmax | I4B | IN | Nside of the map to be created by the alm. |
nlmax | I4B | IN | maximum l value to be considered ( MAX = 3×Nside). |
nmmax | I4B | IN | maximum m value for the alm. |
polar | I4B | IN | equals 1 if polarisation is used, 0 otherwise. |
filename(LEN=filenamelen) | CHR | IN | filename of FITS-file containing powerspectrum. |
iseed | I4B | INOUT | seed for generation of gaussian distributed random numbers to the alm. Set to a negative integer to (re-)initialise the random number generator. On exit iseed will be positive definite. |
fwhm_arcmin | SP | IN | fwhm size of the gaussian beam in arcminutes. |
alm_TGC(1:p,0:nlmax,0:nmmax) | SPC | OUT | complex alm values generated from the powerspectrum in the FITS-file. The first index here runs form 1:1 for temperature only, and 1:3 for polarisation. In the latter case, 1=T, 2=E, 3=B. |
header(LEN=80),dimension(60) | CHR | OUT | part of header which will be included in the FITS-file containing the map synthesised from the alm which create_alm generates. |
windowfile(LEN=filenamelen) (OPTIONAL) | CHR | IN | full filename specification of the FITS file with the pixel window function. |
units(LEN=80),dimension(1:) (OPTIONAL) | CHR | OUT | physical units of the created alm (square-root of the input power spectrum units). |
beam_file(LEN=filenamelen) (OPTIONAL) | CHR | IN | name of the file containing the (non necessarily gaussian) window function Bl of a circular beam. If present, it will override the argument fwhm_arcmin. |
Creates scalar and tensor alm from the powerspectrum given in the file `cl.fits'. The map to be created from these alm is assumed to have Nside = 64. Cls from the powerspectrum are used up to an l value of 128. Corresponding alm values up to l=128 and m=128 are created from a random generator with seed -1. The produced alm are convolved with a gaussian beam of fwhm 5 arcminutes and a pixel window given in the windowfile. It is assumed that after the return from this routine, a map is supposed to be generated from the created alm. For this purpose, a part of a FITS-header for a FITS-file where this map is supposed to be stored, is returned in header.
Eric Hivon 2003-02-07