measure_ee

poppy.measure_ee(hdulist_or_filename=None, ext=0, center=None, binsize=None, normalize='None')

measure encircled energy vs radius and return as an interpolator

Returns a function object which when called returns the Encircled Energy inside a given radius, for any arbitrary desired radius smaller than the image size.

Parameters:

hdulist_or_filenamestring

Either a fits.HDUList object or a filename of a FITS file on disk

extint

Extension in that FITS file

centertuple of floats

Coordinates (x,y) of PSF center. Default is image center.

binsize:

size of step for profile. Default is pixel size.

normalizestring

set to ‘peak’ to normalize peak intensity =1, or to ‘total’ to normalize total flux=1. Default is no normalization (i.e. retain whatever normalization was used in computing the PSF itself)

Returns:

encircled_energy: function

A function which will return the encircled energy interpolated to any desired radius.

Examples

>>> ee = measure_ee("someimage.fits")  
>>> print("The EE at 0.5 arcsec is ", ee(0.5))