org.tensorflow.op.core

Class Substr

java.lang.Object

org.tensorflow.op.PrimitiveOp

org.tensorflow.op.core.Substr

All Implemented Interfaces:

Op, Operand<String>

@Operator
public final class Substr
extends PrimitiveOp
implements Operand<String>

Return substrings from `Tensor` of strings.

For each string in the input `Tensor`, creates a substring starting at index `pos` with a total length of `len`.

If `len` defines a substring that would extend beyond the length of the input string, then as many characters as possible are used.

A negative `pos` indicates distance within the string backwards from the end.

If `pos` specifies an index which is out of range for any of the input strings, then an `InvalidArgumentError` is thrown.

`pos` and `len` must have the same shape, otherwise a `ValueError` is thrown on Op creation.

NOTE: `Substr` supports broadcasting up to two dimensions. More about broadcasting [here](http://docs.scipy.org/doc/numpy/user/basics.broadcasting.html)

---

Examples

Using scalar `pos` and `len`:

 input = [b'Hello', b'World']
 position = 1
 length = 3
 
 output = [b'ell', b'orl']
 

Using `pos` and `len` with same shape as `input`:

 input = [[b'ten', b'eleven', b'twelve'],
          [b'thirteen', b'fourteen', b'fifteen'],
          [b'sixteen', b'seventeen', b'eighteen']]
 position = [[1, 2, 3],
             [1, 2, 3],
             [1, 2, 3]]
 length =   [[2, 3, 4],
             [4, 3, 2],
             [5, 5, 5]]
 
 output = [[b'en', b'eve', b'lve'],
           [b'hirt', b'urt', b'te'],
           [b'ixtee', b'vente', b'hteen']]
 

Broadcasting `pos` and `len` onto `input`:

 input = [[b'ten', b'eleven', b'twelve'],
          [b'thirteen', b'fourteen', b'fifteen'],
          [b'sixteen', b'seventeen', b'eighteen'],
          [b'nineteen', b'twenty', b'twentyone']]
 position = [1, 2, 3]
 length =   [1, 2, 3]
 
 output = [[b'e', b'ev', b'lve'],
           [b'h', b'ur', b'tee'],
           [b'i', b've', b'hte'],
           [b'i', b'en', b'nty']]
 

Broadcasting `input` onto `pos` and `len`:

 input = b'thirteen'
 position = [1, 5, 7]
 length =   [3, 2, 1]
 
 output = [b'hir', b'ee', b'n']
 

Field Summary

Fields inherited from class org.tensorflow.op.PrimitiveOp

operation

Method Summary

Modifier and Type	Method and Description
Output<String>	asOutput() Returns the symbolic handle of a tensor.
static <T extends Number> Substr	create(Scope scope, Operand<String> input, Operand<T> pos, Operand<T> len) Factory method to create a class to wrap a new Substr operation to the graph.
Output<String>	output() Tensor of substrings

Methods inherited from class org.tensorflow.op.PrimitiveOp

equals, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

create

public static <T extends Number> Substr create(Scope scope,
                                               Operand<String> input,
                                               Operand<T> pos,
                                               Operand<T> len)

Factory method to create a class to wrap a new Substr operation to the graph.

Parameters:

scope - current graph scope

input - Tensor of strings

pos - Scalar defining the position of first character in each substring

len - Scalar defining the number of characters to include in each substring

Returns:

a new instance of Substr

output

public Output<String> output()

Tensor of substrings

asOutput

public Output<String> asOutput()

Description copied from interface: Operand

Returns the symbolic handle of a tensor.

Inputs to TensorFlow operations are outputs of another TensorFlow operation. This method is used to obtain a symbolic handle that represents the computation of the input.

Specified by:

asOutput in interface Operand<String>

See Also:

OperationBuilder.addInput(Output)