Filter out nonzero number in array of n*2 dimension.
Show older comments
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.
Accepted Answer
More Answers (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,:) = [];
6 Comments
Chiranjibi
on 16 Jul 2014
James Tursa
on 16 Jul 2014
What is the goal of this? Are you trying to find the indexes of rows that have non-zero numbers in both columns? Or are you trying to construct a new matrix that contains only rows of the original matrix with non-zeros in both columns?
Chiranjibi
on 16 Jul 2014
Joseph Cheng
on 16 Jul 2014
Moreover I just want to delete the rows, which don't have non zero number in same row of both columns.
Thats what James gave you. It finds the rows that are not both are not zero and deletes them.
but in your comment like if 100th row of column first and 100th row of column second only have non zero number I want to kepp only these rows and columns). you say you want to keep the ones that both are not zero.
What are you looking for? simply
- keep row where both do not equal zero
- keep row where either column is zero
- keep row as long as both columns are not zero.
- other?
Chiranjibi
on 16 Jul 2014
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,:);
Categories
Find more on Logical 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!