How to compare rows in a matrix
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Sameer
el 18 de Jul. de 2014
Comentada: Sameer
el 18 de Jul. de 2014
Hello all
I have a matrix A
A =
1 1 0 0 0
0 -1 0 1 0
-1 0 1 1 0
lets say I am looking at the second row in which column 2 and 4 have value present now if I compare it with the row above which has values in the column 1 and column 2 so I want to know the column number which has values in both the rows, I mean here the column number 2 should be returned. Similarly row 3 should be compared with row 1 and 2 and for each row a column number should be returned.
Can anyone please guide me through this.
Regards
1 comentario
Azzi Abdelmalek
el 18 de Jul. de 2014
Editada: Azzi Abdelmalek
el 18 de Jul. de 2014
What is the expected result for your example?
Respuesta aceptada
Azzi Abdelmalek
el 18 de Jul. de 2014
Comparison between row 1 and row 2
A =[ 1 1 0 0 0
0 -1 0 1 0
-1 0 1 1 0]
idx=find(all(A(1:2,:)))
3 comentarios
Azzi Abdelmalek
el 18 de Jul. de 2014
A =[ 1 1 0 0 0
0 -1 0 1 0
-1 0 1 1 0]
jj=0;
for k=2:size(A,1)
for p=1:k-1
B=A([p,k],:)
jj=jj+1;
out{jj,2}=find(all(B))
out{jj,1}=sprintf('(%d,%d)',k,p)
end
end
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the cyclist
el 18 de Jul. de 2014
I think that
[rows,cols] = find(A(2:end,:)~=0 & A(1:end-1,:)~=0)
does what you want.
rows will be the index to the "top" row being compared, and "cols" will be the column numbers that meet your criterion.
For example, in your case
rows = [1; 2];
and
cols = [2; 4];
cols seems to be the main thing you are going for.
2 comentarios
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