NonZero¶

Versioned name: NonZero-3

Category: Condition

Short description: NonZero returns the indices of the non-zero elements of the input tensor.

Detailed description: NonZero returns the indices of the non-zero elements of the input tensor (in row-major order - by dimension).

The output tensor has shape [rank(input), num_non_zero].
For example, for the tensor [[1, 0], [1, 1]] the output will be [[0, 1, 1], [0, 0, 1]].
The output is a collection of tuples, each tuple has rank(input) elements and contains indices for a single non-zero element.
The i’th element of each output dimension is a part of i’th tuple.
In given example the tuples would be: [0, 0], [1, 0], [1, 1].

Attributes

output_type
- Description: the output tensor type
- Range of values: i64 or i32
- Type: string
- Default value: “i64”
- Required: no

Inputs:

1: A tensor of type T and arbitrary shape. Required.

Outputs:

1: tensor with indices of non-zero elements of shape [rank(data), num_non_zero] of type T_OUT.

Types

T: any type.
T_OUT: Depending on output_type attribute can be int64 or int32.

Example

 <layer ... type="NonZero">
     <data output_type="i64"/>
     <input>
         <port id="0">
             <dim>3</dim>
             <dim>10</dim>
             <dim>100</dim>
             <dim>200</dim>
         </port>
     </input>
     <output>
         <port id="1">
             <dim>4</dim>
             <dim>-1</dim>
         </port>
     </output>
 </layer>