function [f, h] = ctfirstorderfilter(type, cutoff, bandwidth)% CTFIRSTORDERFILTER implements continuous time filters, to be used with % cltidemo. %   [f, h] = ctfirstorderfilter(type, cutoff, bandwidth)% where, %   type   - can be one of 'Lowpass', 'Highpass', 'Bandpass' or 'Bandreject'%   cutoff - is the cutoff frequency in Hz. (Max - 200 Hz)%   bandwidth - for Bandpass and Bandreject filters ( 10 to 50 Hz)%  f = linspace(0,200,1001);  fc = cutoff ;  % Bandpass filter - Bandwidth  bw = bandwidth;    switch type   case 'Lowpass'    for i=1:length(f)      h(i) = 1/(1+j*f(i)/fc);    end   case 'Highpass'    for i=1:length(f)      h(i) = (j*f(i)/fc)/(1+j*f(i)/fc);    end   case 'Bandpass'    for i=1:length(f)      h(i) = (j*f(i)*bw)/(f(i)^2 - fc^2 + j*f(i)*bw);    end   case 'Bandreject'    for i=1:length(f)      h(i) = (f(i)^2 - fc^2)/(f(i)^2 - fc^2 + j*f(i)*bw);    end   otherwise    error 'Filter type unknown or unspecified'  end  % endfunction ctfirstorderfilter% eof: ctfirstorderfilter.m