How to compare rows in a matrix

45 visualizaciones (últimos 30 días)
Sameer
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
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?

Iniciar sesión para comentar.

Respuesta aceptada

Azzi Abdelmalek
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
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
Sameer
Sameer el 18 de Jul. de 2014
Thanks a lot

Iniciar sesión para comentar.

Más respuestas (1)

the cyclist
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
the cyclist
the cyclist el 18 de Jul. de 2014
My solution only compares neighboring pairs of rows.
Sameer
Sameer el 18 de Jul. de 2014
Thanks a lot

Iniciar sesión para comentar.

Categorías

Más información sobre MATLAB en Help Center y File Exchange.

Etiquetas

Community Treasure Hunt

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

Start Hunting!

Translated by