how can i find a special row
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
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 Kommentare
Akzeptierte Antwort
Ravi Jhou
am 7 Jun. 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 Kommentare
Ravi Jhou
am 7 Jun. 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.
Weitere Antworten (1)
Roger Stafford
am 6 Jun. 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 Kommentare
Siehe auch
Kategorien
Mehr zu Matrix Indexing finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!