fits2alms*


This routine reads alm values from a binary FITS file. Each FITS file extension is supposed to contain one integer column with index=l2+l+m+1 and 2 or 4 single (or double) precision columns with real/imaginary alm values and real/imaginary standard deviation. One can read temperature alm or temperature and polarisation, aTlm, aElm and aBlm.

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


FORMAT

call fits2alms*( filename, nalms, alms, ncl, header, nlheader, next )


ARGUMENTS

name & dimensionality kind in/out description
       
filename(LEN=filenamelen) CHR IN filename of the FITS-file to read the alm from.
nalms I4B IN number of alm to read.
ncl I4B IN number of columns to read in the FITS file. If an standard deviation is to be read, this number is 5, otherwise it is 3.
next I4B IN the number of extensions to read. 1 for temperature only, 3 for temperature and polarisation.
alms(1:nalms,1:(ncl+1),1:next) SP/ DP OUT the alm to read from the file. alms(i,1,j) and alms(i,2,j) contain the l and m values for the ith alm (j=1,2,3 for (T,E,B)). alms(i,3,j) and alms(i,4,j) contain the real and imaginary value of the ith alm. Finally, the standard deviation for the ith alm is contained in alms(i,5,j) (real) and alms(i,6,j) (imaginary).
nlheader I4B IN number of header lines to read from the file.
header(LEN=80) (1:nlheader, 1:next) CHR OUT the header(s) read from the FITS-file.


EXAMPLE:

call fits2alms ('alms.fits', 65*66/2, alms, 3, header, 80, 3)
Reads a FITS file with the almT, almE and almB values read into alms(1:65*66/2,1:4,1:3). The last index specifies (T,E,B). The second index gives l, m, real( alm ), imaginary( alm ) for each of the alm. The number 65*66/2 is the number of alm values up to an l value of 64. 80 lines is read from the header in each extension and returned in header(1:80,1:3).


MODULES & ROUTINES

This section lists the modules and routines used by fits2alms*.

read_alms
routine called by fits2alms* for each extension.
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 fits2alms*

alms2fits, dump_alms
routines to store alm in a FITS-file
read_conbintab
has the same function as fits2alms* but with parameters passed differently.
number_of_alms, getsize_fits
can be used to find out the number of alm available in the file.

Version 3.31, 2017-01-06