This
j=1;
for i=1:8000
if(abs(x(i))>t)
y1(j)=x(i);
j=j+1;
end
end
can be vectorized:
y1 = zeros(1, length(x); % Initialize to all zeros.
% Compute logical indexes of where x > t
aboveThreshold = x > t;
if sum(aboveThreshold) > 1
% At least one element of x is above the threshold.
% Extract only those above threshold and create a new y1
% which may be a different length than the initialized one.
y1 = x(aboveThreshold);
end
but you still might want to find out why no x is above your t threshold, because though my code fixed your code, it will just continue on with a y of all zeros, which is probably useless and not what you want.
