how to remove zeros from the matrix?
90 views (last 30 days)
Show older comments
Hello, I want to remove zero values from the matrix and cut the last elements of odd rows. For example, if I have a matrix
A=[1, 0, 2, 0, 3 ;
0, 4, 0, 5, 0 ;
6, 0, 7, 0, 8]
and, I want to make matrix like
B=[1, 2;
4, 5;
6, 7]
Please answer this question. Thanks!
5 Comments
Accepted Answer
the cyclist
on 25 Nov 2019
Edited: the cyclist
on 25 Nov 2019
I think this does what you want:
% Replicate A into B
B = A;
% For the even-numbered rows, circularly shift the elements
B(2:2:end,:) = circshift(B(2:2:end,:),-1,2);
% Remove any columnn with a zero
B(:,any(B==0)) = [];
More Answers (3)
Guillaume
on 25 Nov 2019
A=[1, 0, 2, 0, 3 ;
0, 4, 0, 5, 0 ;
6, 0, 7, 0, 8];
B = reshape(nonzeros(A(:, 1:end-1).'), [], size(A, 1)).'
Adam Danz
on 25 Nov 2019
This approach extracts the first two non-zero elements per row. If there are no two non-zero elements in each row an error is thrown.
A=[
1, 0, 2, 0, 3 ;
0, 4, 0, 5, 0 ;
6, 0, 7, 0, 8];
B=[1, 2;
4, 5;
6, 7];
% Number of non-zeros per row or A
numNonZeros = sum(A~=0,2);
% Replace the non-zeros after the 2nd non-zero in
% each row with 0s
A(cumsum(A~=0,2) > 2) = 0;
% Confirm that we end up with 2 non-0s in each row
if (unique(sum(A~=0,2))>0) ~= true
error('Assumption violation: the number of non-zeros in each row of A is unexpected.')
end
A = A.';
B = reshape(A(A~=0),2,size(A,2)).';
Kaspar Bachmann
on 25 Nov 2019
Edited: Kaspar Bachmann
on 25 Nov 2019
A=[1, 0, 2, 0, 3 ; 0, 4, 0, 5, 0 ; 6, 0, 7, 0, 8]
Var = A;
Var(:,length(Var)) = [];
for i = 1:size(Var,1)
t = Var(i,:);
idx = find(t>0);
B(i,:) = t(idx);
end
Its a bit messy, but it should work.
See Also
Categories
Find more on Creating and Concatenating Matrices in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!