|MATLAB Function Reference|
Find indices and values of nonzero elements
k = find(X)
returns the indices of the array
X that point to nonzero elements. If none is found,
find returns an empty matrix.
[i,j] = find(X)
returns the row and column indices of the nonzero entries in the matrix
X. This is often used with sparse matrices.
[i,j,v] = find(X)
returns a column vector
v of the nonzero entries in
X, as well as row and column indices.
X(:), which is the long column vector formed by concatenating the columns of
[i,j,v] = find(X~=0) produces a vector
v with all
1s, and returns the row and column indices.
Some operations on a vector
And on a matrix
colon, logical operators, relational operators