Interpolation Methods

To better understand the different interpolation modes, here are some graphs which use Smooth.js to approximate the sin function. The sin function is first sampled at 8 points, and the resulting array is fed into Smooth.js with different options. The result is plotted in magenta, with the real sin wave plotted in light green for reference.

Nearest Neighbor

Linear

Cubic

Tension parameter = 1

Tension parameter = 0 (Catmull–Rom spline)

Source code

The graphs above were generated by feeding Mac OS X's Grapher the output of the following script:

{Smooth} = require './Smooth'

s = (Math.sin 2*Math.PI*x for x in [0...1] by 1/8)

smooth_sin = Smooth s, {
	clip:Smooth.CLIP_PERIODIC
	method:Smooth.METHOD_LINEAR # change this for different types
}

console.log "#{x.toFixed 2}\t#{smooth_sin(x).toFixed 5}" for x in [0..8] by 0.1