find
find(X) returns indices of non zero elements in matrix X.
- find(X, n) returns the first n indices of non zero elements in X
- find(X, n, str) with str:
- 'first' returns the first n indices
- 'last' returns the last n indices
- [i, j] = find(X) returns rows and columns position of non zero elements in X
- [i, j, v] = find(X) returns rows and columns position of non zero elements in X, as well as their values
Examples
> X = [1 2; 0 3]#
1 2
0 8
> find(X)#
1
3
4
> [i j] = find(X)
[i:3x1 double]
[j:3x1 double]
> i#
1
1
2
> j#
1
2
2
> [i j v] = find(X)
[i:3x1 double]
[j:3x1 double]
[v:3x1 double]
> v#
1
2
8
> x(i(1), j(1)) == v(1)#
1
> find([4 2 9 8 5 6] > 4, 3)#
3 4 5
> find([3 0 1 0 4 0 2], 2, 'last')#
5 7
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