An easy way is to do a pole zero plot using zplane. If you are using one of the standard methods for generating FIR filters 'fir1' 'fir2' 'firls' or 'cremez', the zeros directly on the unit circle are the ones corresponding to the stop band. Also the zeros on the real axis and left half of the plane correspond to the stop band. Everything else is the pass band. Note that under certain cases of equiripple design some zeros on the real axis and the left half of the plane may not conform to the above rule. Jatan --- Appalayagari Sreedhar <> wrote: > Hi, > > I am working on the filter design, > > i am designing the FIR filter, > > i want to know exactly which zeros corresponds to > passband and which zeros to stopband. > > how to get them > > i can get the zeros all by using the command > > tf2zp, > > but i need to separete the passband and stopband > zeros. > > if anyone worked on this idea please send your > valuable suggestions. > > thanks in advance. > > regds,sree. __________________________________________________ |