FITS_tools.downsample.downsample_axis(myarr, factor, axis, estimator=<function nanmean>, truncate=False)[source] [edit on github]

Downsample an ND array by averaging over factor pixels along an axis. Crops right side if the shape is not a multiple of factor.

This code is pure np and should be fast.


myarr : ndarray

The array to downsample

factor : int

The factor to downsample by

axis : int

The axis to downsample along

estimator : function

defaults to mean. You can downsample by summing or something else if you want a different estimator (e.g., downsampling error: you want to sum & divide by sqrt(n))

truncate : bool

Whether to truncate the last chunk or average over a smaller number. e.g., if you downsample [1,2,3,4] by a factor of 3, you could get either [2] or [2,4] if truncate is True or False, respectively.