MATLAB Function Reference |

Find indices and values of nonzero elements

**Syntax**

**Description**

```
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.

In general, `find(X)`

regards `X`

as `X(:)`

, which is the long column vector formed by concatenating the columns of `X`

.

**Examples**

`[i,j,v] = find(X~=0)`

produces a vector `v`

with all `1`

s, and returns the row and column indices.

**See Also**

`nonzeros`

, `sparse`

, `colon`

, logical operators, relational operators

filter2 | findall |