Module sampling 

Resampling (up/down), Interpolation

Functions

downsample

downsample samples from src into dst with the ratio given by src.len()/dst.len() TODO: doc

downsample_sb

uses the nightly step_by adaptor on iterator TODO: doc

interpolate

linearly interpolate n_between samples between each consecutive pair of values in src and write the result to dst. TODO: reference paper which looked at different interpolation techniques and concluded that linear is sufficient for most purposes