
This directory contains data used by various HEALPix codes

pixel_window_n????.fits: 
	pixel window functions w(l) computed for l in [0,4*Nside]
    	for Nside in {2,4,8, ..., 8192}
	They describe the effect of the binning of the signal 
	over finite-size pixels, affecting the angular spectral products:
		a_lm  -> a_lm w(l)
		C_l   -> C_l  w(l)^2
	The temperature and polarization windows are slightly different.


weight_ring_n?????.fits:
	ring-based quadrature weights used to improve the 
	accuracy of finite sum over pixels approximating integrals over the sphere.
	Computed for 2*Nside rings, for Nside in {2,4,8, ..., 8192},
	by the code quad_ring (not publicly available).
	Weights for other Nside values can be computed with the HEALPix/C++ code
	compute_weights (see Healpix/src/cxx/Healpix_cxx/compute_weights.par.txt)
	The values stored are actually the weights minus 1.
	Specific routines are provided to turn these lists into full sky maps
	with 12*Nside^2 pixels.
	The temperature and polarization weights are identical.


weight_pixel_n?????.fits
	pixel-based quadrature weights used to improve the 
	accuracy of finite sum over pixels approximating integrals over the sphere.
	Computed for (3*Nside+1)*(Nside+1)/4 non-redundant locations, 
	for Nside in {8, ..., 2048},
	with the HEALPix/C++ code compute_weights, 
	which can be used to compute other Nside values (see above).
	Note that the results are unstable for Nside < 8, 
	and that the files get large for Nside > 2048.
	The values stored are actually the weights minus 1.
	Specific routines are provided to turn these lists into full sky maps
	with 12*Nside^2 pixels.
	The weights provided are valid for temperature and polarization.


2018-05-24 	E. Hivon

