freqpw.m

来自「里面囊括了基于matlab滤波器设计的各种.m文件」· M 代码 · 共 28 行

 
% F = FREQPW(B,A,color)
%
% The same as the FREQPLOT, but using FREQZ(B,A,N,'WHOLE')
% This function is used to plot the amplitude response of filter
% or signal. A logarithmic (base 10) scale is used for the Y-axis.
% X-axis is normalized freqency from 0 to 0.5. The color will be
% the one specified in argument. If there is no color specification,
% the color will be white. Also see DPLOT
%

function F = freqpw(B,A,c)

 if nargin == 2
  c = 'w';
 end

 [F,W]=freqz(B,A,1024,'whole');
 W=linspace(0,1.0,1024);
 F_ABS = abs(F);

 %F_DB = dbvalue(F_ABS/max(F_ABS));

 F_DB = dbvalue(F_ABS);
 plot(W,F_DB,c)
 
 xlabel('Normalized Frequency');
 ylabel('Magnitude(dB)');