ring_pixel_geo.py

"""a healpix pixelated geo of disk of sky with certain number of ring ordered healpix pixels"""
from __future__ import division,print_function,absolute_import
from builtins import range

import numpy as np

from polygon_utils import get_healpix_pixelation
from pixel_geo import PixelGeo

class RingPixelGeo(PixelGeo):
    """healpix pixelated geo of entire sky"""
    def __init__(self,zs,C,z_fine,l_max,res_healpix,n_pix,all_pixels=None):
        """create a geo with the first n_pix healpix pixels
                inputs:
                    zs: the tomographic z bins
                    C: a CosmoPie object
                    z_fine: the resolution z slices
                    l_max: the maximum l to compute the alm table to
                    res_healpix: 4 to 9, healpix resolution to use
                    n_pix: number of pixels to include
        """
        self.C = C
        self.z_fine = z_fine
        self.res_healpix = res_healpix
        self.n_pix = n_pix
        hard_l_max = 3.*2**self.res_healpix-1.
        if all_pixels is None:
            self.all_pixels = get_healpix_pixelation(res_choose=self.res_healpix)
        else:
            self.all_pixels = all_pixels
        self.contained =  np.full(self.all_pixels.shape[0],False)
        self.contained[0:n_pix] = True
        contained_pixels = self.all_pixels[0:n_pix]

        print("RingPixelGeo: total contained pixels in polygon: "+str(np.sum(self.contained*1.)))
        PixelGeo.__init__(self,zs,contained_pixels,C,z_fine,l_max,hard_l_max)

    def get_overlap_fraction(self,geo2):
        """get overlap fraction between this geometry and another PolygonPixelGeo"""
        result = np.sum(self.contained*geo2.contained)*1./np.sum(self.contained)
        return result
#    def get_overlap_fraction(self,geo2):
#        """get overlap fraction between this geometry and another PolygonPixelGeo"""
#        return geo2.angular_area()/self.angular_area()