FilterEMG

close all; clear all; clc;

load EMGData.txt
emg = EMGData(:,1);

[b,a]=butter(4,4/(960/2),'low');

n = length(a);
z(n) = 0;
Y = zeros(size(X));
for m = 1:length(Y)
%    disp(['b(0): ' num2str(b(1))]);
%    disp(['X(m): ' num2str(X(m))]);
%    disp(['z(0): ' num2str(z(1))]);
   Y(m) = b(1) * X(m) + z(1);
%    disp(['Y(m)=b(0)*X(m)+z(0) : ' num2str(Y(m))]);
   for i = 2:n
%       disp(['for i=' num2str(i-1)]);
%       disp(['  b(' num2str(i-1) '):' num2str(b(i))]);
%       disp(['  X(m):' num2str(X(m))]);
%       disp(['  z(' num2str(i-1) '):' num2str(z(i))]);
%       disp(['  a(' num2str(i-1) '):' num2str(a(i))]);
%       disp(['  Y(m):' num2str(Y(m))]);
      z(i - 1) = b(i) * X(m) + z(i) - a(i) * Y(m);
%       disp(['Z(' num2str(i-2) ')=b(i)*X(m)+z(i)-a(i)*Y(m):' num2str(z(i-1))]);
   end
%   disp('--------------------------------------');
end
z = z(1:n - 1);

figure
plot(X)
hold on
plot(Y,'LineWidth',3,'Color','black')
axis tight