how can i find a special row
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
How can i find a row which including only -1. In that A matrix how can i write a code
A=[-1,-1,0,0,0;0,0,0,-1,0;0,1,-1,0,-1;0,0,1,0,0;1,0,0,1,1]
0 commentaires
Réponse acceptée
Ravi Jhou
le 7 Juin 2013
You could try
blnA = logical( A == -1 );
blnOut = find( sum( blnA' ) == 1 );
variable 'blnA' finds the elements of matrix A, which are equal to -1.
The output of blnA is
blnA =
1 1 0 0 0
0 0 0 1 0
0 0 1 0 1
0 0 0 0 0
0 1 0 0 0
if there is just one '-1', the summary for each row of logical matrix blnA will be '1'.
And because the command 'sum' sums the elements of column.
So need to do a transpose.
The output of blnOut
blnOut =
2
A ha, row 2. Got it.
4 commentaires
Ravi Jhou
le 7 Juin 2013
You confused me.
Let me describe what you want.
e.g.
A = [-1 1 1 ;
0 -1 0 ;
0 0 -1 ;
1 0 0];
you want to find row 1, 2 ,and 3, which are included at least one '-1'.
or, you want to find row 2 and 3, which are included only one non-zero element '-1'.
You have to describe your question clearly, so I could answer you exactly.
Plus de réponses (1)
Roger Stafford
le 6 Juin 2013
I am guessing that you mean, how can you find those rows each of which includes at least one -1. Is that what you mean? If so, do this:
f = find(any(A==-1,2));
3 commentaires
Voir également
Catégories
En savoir plus sur Matrix Indexing dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!