Upsample
Data upsampling increases the resolution of the data by interpolating between samples. The following methods of upsampling are available:
Nearest Neighbor – the simplest method of interpolation, in which the interpolants are chosen as the nearest datapoint.
Linear Interpolation – a coarse interpolation method in which the interpolants are chosen to lie on a straight line between adjacent datapoints.
Cubic Spline Interpolation – a sophisticated interpolation technique in which interpolants are chosen to lie on 3rd-order piecewise polynomials between adjacent data points. The polynomial coefficients are set to ensure the interpolated function is continuous at the first and second derivative.
For most purposes cubic spline interpolation is optimal as it produces the smoothest interpolation.