GLESP pixelization      

HEALpix pixelization:

• The relevant S2HAT pixelization structure, pixelization, of type s2hat_pixeltype, describing this scheme is set by calling
  
  
  set_pixelization( PIXCHOICE_HEALPIX, pixpars, pixelization),
  
  where PIXCHOICE_HEALPIX is a predefined S2HAT parameter (4-byte integer set to 0) and the field par1 of the variable pixpars (of type s2hat_pixparameters) is set to nside, i.e., the HEALpix resolution parameter. (The values of the other field(s) are irrelevant.)
  
  Check here or here to find more about the set_pixelization routine in Fortran 90 and C, respectively.
  
  Note that since version 2.5 the library does not any more require to be linked to HEALpix. Nevertheless, the HEALPix pixelization basic definitions are supported internally by S2HAT, though limited only to the ring ordering, and follow all the standard HEALPix conventions and rules as described in Gorski et al. paper (see below). Consequently, it is fully consistent with the HEALPix package (at least as is up to version 2.1). S2HAT however does not duplicate HEALPix and therefore the other HEALPix funcionality, such as all the operations and manipulations performed on HEALPix maps etc., is not provided here and it requires the HEALPix library to be linked as well.
  
  We note that linking the HEALPix library does not mean that HEALPix FFT routine has to be used.
  
  For more details see:
  • HEALpix home page;
  • HEALpix paper
    by K.M. Gorski, E. Hivon, A.J. Banday, B.D. Wandelt, F.K. Hansen, M. Rainecke, and M. Bartelmann.