# tensorflow::ops::GatherNd

`#include <array_ops.h>`

[Gather](https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/gather#classtensorflow_1_1ops_1_1_gather) slices from `params` into a [Tensor](https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/tensor#classtensorflow_1_1_tensor) with shape specified by `indices`.

## Summary

`indices` is a K-dimensional integer tensor, best thought of as a (K-1)-dimensional tensor of indices into `params`, where each element defines a slice of `params`:

```
output[\\(i_0, ..., i_{K-2}\\)] = params[indices[\\(i_0, ..., i_{K-2}\\)]]
```

<br />

Whereas in `tf.gather``indices` defines slices into the first dimension of `params`, in `tf.gather_nd`, `indices` defines slices into the first `N` dimensions of `params`, where `N = indices.shape[-1]`.

The last dimension of `indices` can be at most the rank of `params`:

```
indices.shape[-1] <= params.rank
```

<br />

The last dimension of `indices` corresponds to elements (if `indices.shape[-1] == params.rank`) or slices (if `indices.shape[-1] < params.rank`) along dimension `indices.shape[-1]` of `params`. The output tensor has shape

```
indices.shape[:-1] + params.shape[indices.shape[-1]:]
```

<br />

Note that on CPU, if an out of bound index is found, an error is returned. On GPU, if an out of bound index is found, a 0 is stored in the corresponding output value.

Some examples below.

Simple indexing into a matrix:


```
    indices = [[0, 0], [1, 1]]
    params = [['a', 'b'], ['c', 'd']]
    output = ['a', 'd']
```

<br />

Slice indexing into a matrix:


```
    indices = [[1], [0]]
    params = [['a', 'b'], ['c', 'd']]
    output = [['c', 'd'], ['a', 'b']]
```

<br />

Indexing into a 3-tensor:


```
    indices = [[1]]
    params = [[['a0', 'b0'], ['c0', 'd0']],
              [['a1', 'b1'], ['c1', 'd1']]]
    output = [[['a1', 'b1'], ['c1', 'd1']]]
```

<br />


```
    indices = [[0, 1], [1, 0]]
    params = [[['a0', 'b0'], ['c0', 'd0']],
              [['a1', 'b1'], ['c1', 'd1']]]
    output = [['c0', 'd0'], ['a1', 'b1']]
```

<br />


```
    indices = [[0, 0, 1], [1, 0, 1]]
    params = [[['a0', 'b0'], ['c0', 'd0']],
              [['a1', 'b1'], ['c1', 'd1']]]
    output = ['b0', 'b1']
```

<br />

Batched indexing into a matrix:


```
    indices = [[[0, 0]], [[0, 1]]]
    params = [['a', 'b'], ['c', 'd']]
    output = [['a'], ['b']]
```

<br />

Batched slice indexing into a matrix:


```
    indices = [[[1]], [[0]]]
    params = [['a', 'b'], ['c', 'd']]
    output = [[['c', 'd']], [['a', 'b']]]
```

<br />

Batched indexing into a 3-tensor:


```
    indices = [[[1]], [[0]]]
    params = [[['a0', 'b0'], ['c0', 'd0']],
              [['a1', 'b1'], ['c1', 'd1']]]
    output = [[[['a1', 'b1'], ['c1', 'd1']]],
              [[['a0', 'b0'], ['c0', 'd0']]]]
```

<br />


```
    indices = [[[0, 1], [1, 0]], [[0, 0], [1, 1]]]
    params = [[['a0', 'b0'], ['c0', 'd0']],
              [['a1', 'b1'], ['c1', 'd1']]]
    output = [[['c0', 'd0'], ['a1', 'b1']],
              [['a0', 'b0'], ['c1', 'd1']]]
```

<br />


```
    indices = [[[0, 0, 1], [1, 0, 1]], [[0, 1, 1], [1, 1, 0]]]
    params = [[['a0', 'b0'], ['c0', 'd0']],
              [['a1', 'b1'], ['c1', 'd1']]]
    output = [['b0', 'b1'], ['d0', 'c1']]
```

<br />

See also `tf.gather` and `tf.batch_gather`.

Arguments:

- scope: A [Scope](https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/scope#classtensorflow_1_1_scope) object
- params: The tensor from which to gather values.
- indices: Index tensor.

<br />

Returns:

- `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/output#classtensorflow_1_1_output`: Values from `params` gathered from indices given by `indices`, with shape `indices.shape[:-1] + params.shape[indices.shape[-1]:]`.

<br />

| ### Constructors and Destructors ||
|---|---|
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/gather-nd#classtensorflow_1_1ops_1_1_gather_nd_1a83ac49d5f8899faa1cf24f7eea2c01ac(const ::https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/scope#classtensorflow_1_1_scope & scope, ::https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/input#classtensorflow_1_1_input params, ::https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/input#classtensorflow_1_1_input indices)` ||

| ### Public attributes ||
|---|---|
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/gather-nd#classtensorflow_1_1ops_1_1_gather_nd_1a3ef794c722311cc2b178e09e32c48f15` | `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/operation#classtensorflow_1_1_operation` |
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/gather-nd#classtensorflow_1_1ops_1_1_gather_nd_1a3e99a0c52482bb14c94c1bbf9b507e95` | `::https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/output#classtensorflow_1_1_output` |

| ### Public functions ||
|---|---|
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/gather-nd#classtensorflow_1_1ops_1_1_gather_nd_1ab32d5802ad22d9fa803952390ca3fce8() const ` | `::tensorflow::Node *` |
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/gather-nd#classtensorflow_1_1ops_1_1_gather_nd_1ab8601c2824b77c2f890a973ccd8f7212() const ` | ` `` ` |
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/gather-nd#classtensorflow_1_1ops_1_1_gather_nd_1a7741e14bd7240a514268290545b62223() const ` | ` `` ` |

## Public attributes

### operation

```
Operation operation
```

### output

```
::tensorflow::Output output
```

## Public functions

### GatherNd

```
 GatherNd(
  const ::tensorflow::Scope & scope,
  ::tensorflow::Input params,
  ::tensorflow::Input indices
)
```

### node

```
::tensorflow::Node * node() const 
```

### operator::tensorflow::Input

```
 operator::tensorflow::Input() const 
```

### operator::tensorflow::Output

```
 operator::tensorflow::Output() const 
```