# Method trueIdx

#### static member trueIdx: Tensor<bool> -> Tensor<int64>

Finds the indices of all element that are true.

##### Declaration

`static member trueIdx: src:Tensor<bool> -> Tensor<int64>`

##### Parameters

Type | Name | Description |
---|---|---|

Tensor<bool> | src | The tensor containing the source values. |

##### Returns

Type | Description |
---|---|

Tensor<int64> | A matrix that has one row per true entry in |

##### Remarks

The function searches for elements that are true and for each one it creates a row in the result matrix consisting of the indices of the element.

##### Examples

```
let a = HostTensor.ofList2D [[true; false; true; false]
[false; true; true; false]]
let b = Tensor.trueIdx a // b = [[0L; 0L]
// [0L; 2L]
// [1L; 1L]
// [1L; 2L]]
```