# Filter out nonzero number in array of n*2 dimension.

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Chiranjibi on 16 Jul 2014
Commented: Joseph Cheng on 16 Jul 2014
I have two column and 208k rows array, each row is event number. My array is like that,
3145728 0
0 3
0 3
0 3
3145728 0
0 192
0 0
384 0
48 0
3145728 0
3145728 0
0 384
0 3
2097152 0
0 3
3145728 0
0 3
0 3
0 3
16777216 0
This is only for 20 events.Here, it look like randomly numbered of zero and non zero(i.e one row non zero and other row zero and vice-versa for each event). So can anybody please give me idea that how to filter out if there are non zero numbers in the same row of both column through matlab script.

Azzi Abdelmalek on 16 Jul 2014
A(all(A,2),:)

James Tursa on 16 Jul 2014
If I understand your question, you want to delete the rows with non-zero entries in both columns, e.g.,
idx = sum(A~=0,2)==2;
A(idx,:) = [];
Joseph Cheng on 16 Jul 2014
then just modify what James supplied. As you can see he first finds the index where there are non zeros in both.
So we can change it to
ind = sum(A,2)==0;
which will each column to each other. Check if rows equal zero and now we have which ones are equal to zero.
Then we can do A(ind,:)=[] which will get rid of all rows which add up to zero.

Daniel on 16 Jul 2014
matrix = [3145728,0;...
0,3;...
0,3;...
0,3;...
3145728,0;...
0,192;...
0,0;...
384,0;...
48,0;...
3145728,0;...
3145728,0;...
0,384;...
0,3;...
2097152,0;...
0,3;...
3145728,0;...
0,3;...
0,3;...
0,3;...
16777216,0];
Indices = matrix(:,1) ~= 0 | matrix(:,2) ~= 0;
matrix = matrix(Indices,:);