# Frequency response of a filter - fft vs. freqz

I have designed my filter using firhalfband(N,Fo,A), which gives me the filter coefficients. Then I try to see the frequency response of it. I use these two function: fft, and freqz, but they are giving me different result in my figure, why is that? I wonder how these two MATLAB functions operate when taking the frequency response of a signal. I am expecting them to be the same.

Thank you

• There is no need to duplicate posts on the same topic. Here is answer that should help you. Basically output from the fft must be scaled and represented properly. – jojek Aug 3 '14 at 11:37