% MEANSOF4.M - Filters In to produce Out using running means of 4
% with coefficients b(1:4)

l = length(In);

% coefficients
b = [0.25 0.25 0.25 0.25];

Out = zeros(l,1);
Out(4:l) = b(1)*In(4:l) + b(2)*In(3:l-1) + b(3)*In(2:l-2) + b(4)*In(1:l-3);