System Identification Toolbox

resample

Resample data by interpolation and decimation.

Syntax

• datar = resample(data,P,Q)
  datar = resample(data,P,Q,,filter_order)
  

Description

data: The data to be resampled, given as an iddata object

datar: The resampled data returned as an iddata object

P,Q: Integers that determine the resampling factor. The new sampling interval will be Q/P times the original one, so resample(z,1,Q) means decimation with a factor Q.

filter_order: Determines the order of the presampling filters used before interpolation and decimation. Default is 10.

Algorithm

If the Signal Processing Toolbox is available, the resampling is achieved by calls to the resample function in that toolbox. The intersample character of the input, as described by data.InterSample, is taken into account.

Otherwise, the data are interpolated by a factor P and then decimated by a factor Q. The interpolation and decimation are preceded by prefiltering, and follow the same algorithms as in the routines interp and decimate in the Signal Processing Toolbox.

Examples

Resample by a increasing the sampling rate a factor1.5 and compare the signals.

• plot(u)
  ur = resample(u,3,2);
  plot(u,ur)
  

rbj

resid