# How to remove zeroes not defined by indices

2 views (last 30 days)
Suraj on 5 Nov 2020
Edited: Suraj on 6 Nov 2020
Hello All,
I have a large signal data file (about 3000000x1 double) and I first ran these values under a defined signal range and replaced the non conforming values to zero.
However, some of the values of the original data also contain zeroes for which I have the corresponding indices.
1. How do I remove the other zeroes from the data but keep the zeroes corresponding to the indices?
Eg: 1. A = [ 1 2 0 0 3 0 4 0 5 6 0 9] -> Data
B = [3,6,8] -> Indices corresponding to the zeroes in A
Expected Output: [1 2 0 3 0 4 0 5 6 9]
Below is a code snippet for this logic that I tried but without success.
%Thr = Measured Data Signal (Appox. 3000000 x 1 double)
%idx = Indices for zeros to be retained in data signal
Thr2 = zeros(size(Thr));
Thr3 = Thr;
for k = 1:numel(idx)
Thr2(idx(k)) = idx(k);
end
for k1 = 1:numel(Thr)
if((Thr(k1)== 0)&&(k ~= Thr2(k)))
Thr3(k1) = [];
else
Thr3(k1) = Thr3(k1);
end
end
Any help would be appreciated.
Cheers!
##### 2 CommentsShowHide 1 older comment
Suraj on 5 Nov 2020
In the example, B corresponds to the indices of the values that are equal to zero and that which need to be retained.
Therefore, only the zeroes that are present in the index values 3,6,8 need to be retained and the other zeroes (In indices 4, 11] need to be removed.
Thanks!

madhan ravi on 5 Nov 2020
Edited: madhan ravi on 5 Nov 2020
Wanted = zeros(numel(nonzeros(A)) + numel(B), 1);
Wanted(setdiff(1 : numel(Wanted), B)) = nonzeros(A)
Suraj on 6 Nov 2020

R2019b

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!