How to write the matlab code for decimation filter?

[triump.ar]

how to write the matlab code for decimation filter...consisting of one comb filter followed by two fir filter....how to start ...and which points to b considered for the design...

 

[XHL]

decimation filter

firstly - what do you want to get, just to see the frequency response or get the decimated data out.

use freqz(h) to view the response.

and use conv(h, input) to get output then do decimate - just as out = out(1:decimate_ratio:end)