MATLAB: How to deal with this error?

Signal Processing Toolboxundefined function

A model of the surface EMG signal is created by filtering a white gaussian noise, using a shaping filter H(f). this filter has low cut-off freq=60hz and high cut-off freq=120hz. this is my code but i don't know how to deal with Undefined function 'designfilt' for input arguments of type 'char'.
clear all;  
    subplot(322);
    load nnoise.m;
    plot(nnoise,'k');
 % design shaping filter
   bpFilt = designfilt('bandpassfir',...
         'CutoffFrequency1',60,'CutoffFrequency2',120, ...
         'SampleRate',2000);
     subplot(323);
     W = filter(bpFilt,nnoise);
     plot(W,'k');title ('EMG');

Best Answer

The designfilt function was introduced in the R2014a version of the Signal Processing Toolbox.
If you have an earlier version of the Signal Processing Toolbox, this filter will work, since all the functions were introduced prior to R2006a:
Fs = 2000;
notch_frq = [50 60 120 130];
mags = [0 1 0];
devs = [0.05  0.01  0.05];
[n,Wn,beta,ftype] = kaiserord(notch_frq,mags,devs,Fs);
n = n + rem(n,2);
hh = fir1(n,Wn,ftype,kaiser(n+1,beta),'scale');
figure(1)
freqz(hh, 1, 2^17, Fs)
Use the filtfilt function to do the actual filtering of your signal.
See the documentation on the various functions to understand how to use them.
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