Polynomial Interpolation

Polynomial interpolation allows oversampling or undersampling a waveform using any order polynomial set by the property Measurement Polynomial Interpolation Order. As an example, an order of 1 corresponds to linear interpolation. The new number of points is determined by the input size times Measurement Interpolation Sampling Factor. The sampling factor can be any number greater than 0.

For every consecutive (order + 1) number of points, a polynomial is fit to the points, and new points are interpolated in a region of size dx in the middle of these order + 1 points, where dx is the original x spacing between two points in the waveform. This results in the interpolation shrinking the total x size of the waveform, since points cannot be accurately interpolated near the boundaries. In particular, the waveform loses 0.5 × dx × (order – 1) amount of x range at both the beginning and the end of the waveform.

Units

Volts

X Units

Seconds

Resulting Array Size

inputSize × Measurement Interpolation Sampling Factor