keras/keras_core/layers/merging/subtract.py
Aakash Kumar Nain a31e96fed7 Add subtract layer (#69)
* add base merge layer

* format docstrings

* add  layer

* add test cases for  layer

* Add import for  layer

* fix build function

* add dynamic and static tests

* fix pytest import

* fix pytest decorator

* remove batch size from dynamic shape test

* fix keras reference

* refactor test class

* fix tf tests, and linting issues

* add subtract layer

* add tests for subtract layer

* fix linting issues
2023-05-02 22:19:43 +05:30

82 lines
2.7 KiB
Python

from keras_core.api_export import keras_core_export
from keras_core.layers.merging.base_merge import Merge
@keras_core_export("keras_core.layers.Subtract")
class Subtract(Merge):
"""Performs elementwise subtraction.
It takes as input a list of tensors of size 2 both of the
same shape, and returns a single tensor (inputs[0] - inputs[1])
of same shape.
Examples:
>>> input_shape = (2, 3, 4)
>>> x1 = np.random.rand(*input_shape)
>>> x2 = np.random.rand(*input_shape)
>>> y = keras_core.layers.Subtract()([x1, x2])
Usage in a Keras model:
>>> input1 = keras_core.layers.Input(shape=(16,))
>>> x1 = keras_core.layers.Dense(8, activation='relu')(input1)
>>> input2 = keras_core.layers.Input(shape=(32,))
>>> x2 = keras_core.layers.Dense(8, activation='relu')(input2)
>>> # equivalent to `subtracted = keras_core.layers.subtract([x1, x2])`
>>> subtracted = keras_core.layers.Subtract()([x1, x2])
>>> out = keras_core.layers.Dense(4)(subtracted)
>>> model = keras_core.models.Model(inputs=[input1, input2], outputs=out)
"""
def build(self, input_shape):
super().build(input_shape)
if len(input_shape) != 2:
raise ValueError(
"A `Subtract` layer should be called on exactly 2 inputs. "
f"Received: input_shape={input_shape}"
)
def _merge_function(self, inputs):
if len(inputs) != 2:
raise ValueError(
"A `Subtract` layer should be called on exactly 2 inputs. "
f"Received: inputs={inputs}"
)
return inputs[0] - inputs[1]
@keras_core_export("keras_core.layers.subtract")
def subtract(inputs, **kwargs):
"""Functional interface to the `keras_core.layers.Subtract` layer.
Args:
inputs: A list of input tensors of size 2, each tensor of
the same shape.
**kwargs: Standard layer keyword arguments.
Returns:
A tensor as the difference of the inputs. It has the same shape
as the inputs.
Examples:
>>> input_shape = (2, 3, 4)
>>> x1 = np.random.rand(*input_shape)
>>> x2 = np.random.rand(*input_shape)
>>> y = keras_core.layers.subtract([x1, x2])
Usage in a Keras model:
>>> input1 = keras_core.layers.Input(shape=(16,))
>>> x1 = keras_core.layers.Dense(8, activation='relu')(input1)
>>> input2 = keras_core.layers.Input(shape=(32,))
>>> x2 = keras_core.layers.Dense(8, activation='relu')(input2)
>>> subtracted = keras_core.layers.subtract([x1, x2])
>>> out = keras_core.layers.Dense(4)(subtracted)
>>> model = keras_core.models.Model(inputs=[input1, input2], outputs=out)
"""
return Subtract(**kwargs)(inputs)