decimate Decimation — decrease sample rate by integer factor y = decimate(x,q) y = decimate(x,q,n) y = decimate (…, "fir") x: input sequence q: reduction factor n: filter order ftype: filter type: iir or fir y = decimate(x,q) reduces the sample rate of x, the input signal, by a factor of q. By default, an order n Chebyshev type I filter is used. If n is not specified, the default is 8. If the optional argument "fir" is given, an order n FIR filter is used, with a default order of 30 if n is not given. Note that q must be an integer for this rate change method. Ayush Baid