How select a first value from the binary matrix ?
3 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
vikash kumar
el 19 de Ag. de 2019
Editada: Andrei Bobrov
el 22 de Ag. de 2019
I have below matrix i want to select one value from each column which will be 1 make other 0 at return i will get 10*10 matrix.Selection of 1 such that a11 from 1st column,a22 from 2 column,a13 from the third column,a14 from the 4column and so on and make other value in the column 0.If we go for the indexing is ok for the small matrix but in bigger matrix we don't know the position of the 1 value.So is it possible to changed what i want.I have 1300*500 size matrix this is only for the example.
Thanks in advanced for your help.
matrix = [
0 1 0 0 1 0 0 1 0 1 0 1 1 1 0 1 0 0 1 0
1 1 0 0 1 1 1 0 0 1 0 1 0 1 0 0 1 1 1 1
0 1 1 0 0 1 1 0 1 1 1 0 0 1 1 0 0 0 1 1
0 1 1 1 1 1 1 0 0 0 0 1 0 1 1 0 0 0 1 0
1 1 0 0 0 1 0 0 1 1 1 1 0 0 0 0 0 0 0 1
0 0 0 0 0 1 0 0 1 0 1 1 0 1 1 1 1 1 1 0
1 0 1 0 1 0 0 1 1 0 1 1 0 0 1 0 0 1 0 1
1 1 0 0 1 0 1 0 0 0 0 0 1 1 0 1 1 1 0 1
1 0 1 0 0 1 0 0 1 0 0 0 0 1 1 0 0 0 1 0
0 0 1 0 1 0 1 1 0 0 0 1 1 0 0 0 1 1 0 1
];
1 comentario
Respuesta aceptada
Andrei Bobrov
el 20 de Ag. de 2019
Editada: Andrei Bobrov
el 22 de Ag. de 2019
out = cumsum(cumsum(matrix)) == 1;
or
out = cumsum(matrix) == 1 & matrix;
Más respuestas (1)
Walter Roberson
el 19 de Ag. de 2019
Editada: Walter Roberson
el 19 de Ag. de 2019
[~,idx] = max(matrix);
output = sparse(idx,1:size(matrix,2),1,size(matrix,1),size(matrix,2));
Note: in the case where there are no 1's in a particular column, then this code will pick the first row of that column.
[~,idx] = max(matrix);
output = sparse(idx,1:size(matrix,2),true,size(matrix,1),size(matrix,2));
is potentially more useful for your purposes.
5 comentarios
Walter Roberson
el 20 de Ag. de 2019
With your 1300 x 500 array, only 1 in 1300 rows has a non-zero entry for each column, so sparse can be a lot more storage efficient than full(); in my test, the full version takes 41 times more memory.
Ver también
Categorías
Más información sobre Structures en Help Center y File Exchange.
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!