interpolate

DSP.interpolate(data, increase)

Interpolate data increasing the number of points by a factor of increase which must be a power of two.

Notes

fft() of N samples returns N spectral points. To interpolate, simply at increase-1 times N zeros and call ifft().

rfft() of N samples returns N//2+1 complex spectral points. We expect N*increase new data points. Its transform has (N*increase)//2+1 data points.