%% Even-Order Antisymmetric FIR Filter Structure
% Create a 44th-order lowpass direct-form antisymmetric FIR differentiator filter structure for a dfilt object.

Num_coeffs = firpm(44,[0 .3 .4 1],[0 .2 0 0],'differentiator');
Hd = dfilt.dfasymfir(Num_coeffs);

%
% Display the impulse response of the filter.

impz(Hd)

% Copyright 2012 The MathWorks, Inc.