%?script?file:?fir_filter.m
%
%?Purpose:
%???Design?an?FIR?filter?using??window?function
%?
%?Record?of?revisions
%?????Date????????Programmer????????Description?of?change
%????======???????==========????????=====================
%???04/22/2010????zhangyp???????????Origianl?code
%
%?Define?variables
%???wc????????--?wc?is?cutoff?frequency.
%???N?????????--?The?finite?length
%???h?????????--?The?response?array
%???h1????????--?Respone?array?before?add?window
%???iijj?????--?Loop?index
%???w_index???--?Window?index
%???w?????????--?Window?function
%???f_index???--?Filter?kind?index
%???alpha?????--?alpha=（N-1）/2
%???wlwh?????--?parameter?of?bandpass?and?band-reject
%???hw????????--?FFT?of?h
%???hw_shift??--?Shift?of?hw?512?point
%???hw_shift1?--?Shift?of?hw?256?point