fusionlab.nn.components.CrossAttention

class fusionlab.nn.components.CrossAttention

Bases: Layer, NNLearner

CrossAttention that attends source1 (query) to source2 (key/value) with optional masks.

attention_maskTensor, optional

Bool / 0‑1 mask broadcastable to (B, Tq, Tv). Passed directly to Keras MultiHeadAttention.

query_mask, value_maskTensor, optional

1D/2D masks (B, Tq) or (B, Tv). If provided and attention_mask is None, they are combined to form (B, Tq, Tv).

use_causal_maskbool

Forwarded to MHA. Default False.

__init__(units, num_heads)

Parameters:

• units (int)

• num_heads (int)

Methods

__init__(units, num_heads)
add_loss(loss)	Can be called inside of the call() method to add a scalar loss.
add_metric(*args, **kwargs)
add_variable(shape, initializer[, dtype, ...])	Add a weight variable to the layer.
add_weight([shape, initializer, dtype, ...])	Add a weight variable to the layer.
build(input_shape)
build_from_config(config)	Builds the layer's states with the supplied config dict.
call(inputs[, training, attention_mask, ...])	Forward pass of CrossAttention.
compute_mask(inputs, previous_mask)
compute_output_shape(*args, **kwargs)
compute_output_spec(*args, **kwargs)
count_params()	Count the total number of scalars composing the weights.
from_config(config)	Creates an operation from its config.
get_build_config()	Returns a dictionary with the layer's input shape.
get_config()	Returns the config of the object.
get_params([deep])	Get the parameters for this learner.
get_weights()	Return the values of layer.weights as a list of NumPy arrays.
help(**kwargs)
load(file_path[, format])	Load the learner's state from a specified file in the desired format.
load_own_variables(store)	Loads the state of the layer.
quantize(mode[, type_check, config])
quantized_build(input_shape, mode)
quantized_call(*args, **kwargs)
rematerialized_call(layer_call, *args, **kwargs)	Enable rematerialization dynamically for layer's call method.
save([file_path, format, overwrite, ...])	Save the learner's state to a specified file in the desired format.
save_own_variables(store)	Saves the state of the layer.
set_params(**params)	Set the parameters of this learner.
set_weights(weights)	Sets the values of layer.weights from a list of NumPy arrays.
stateless_call(trainable_variables, ...[, ...])	Call the layer without any side effects.
summary()	Provide a summary of the learner's parameters.
symbolic_call(*args, **kwargs)

Attributes

compute_dtype	The dtype of the computations performed by the layer.
dtype	Alias of layer.variable_dtype.
dtype_policy
input	Retrieves the input tensor(s) of a symbolic operation.
input_dtype	The dtype layer inputs should be converted to.
input_spec
losses	List of scalar losses from add_loss, regularizers and sublayers.
metrics	List of all metrics.
metrics_variables	List of all metric variables.
my_params
non_trainable_variables	List of all non-trainable layer state.
non_trainable_weights	List of all non-trainable weight variables of the layer.
output	Retrieves the output tensor(s) of a layer.
path	The path of the layer.
quantization_mode	The quantization mode of this layer, None if not quantized.
supports_masking	Whether this layer supports computing a mask using compute_mask.
trainable	Settable boolean, whether this layer should be trainable or not.
trainable_variables	List of all trainable layer state.
trainable_weights	List of all trainable weight variables of the layer.
variable_dtype	The dtype of the state (weights) of the layer.
variables	List of all layer state, including random seeds.
weights	List of all weight variables of the layer.

__init__(units, num_heads)

Parameters:

• units (int)

• num_heads (int)

call(inputs, training=False, *, attention_mask=None, query_mask=None, value_mask=None, use_causal_mask=False, **kwargs)

Forward pass of CrossAttention.

Parameters:

• inputs (list of tf.Tensor) – A list [source1, source2], each of shape (batch_size, time_steps, features).

• training (bool, optional) – Indicates if the layer is in training mode (for dropout, if any). Defaults to False.

• attention_mask (Tensor, optional) – Bool / 0‑1 mask broadcastable to (B, Tq, Tv). Passed directly to Keras MultiHeadAttention.

• query_mask (Tensor, optional) – 1D/2D masks (B, Tq) or (B, Tv). If provided and attention_mask is None, they are combined to form (B, Tq, Tv).

• value_mask (Tensor, optional) – 1D/2D masks (B, Tq) or (B, Tv). If provided and attention_mask is None, they are combined to form (B, Tq, Tv).

• use_causal_mask (bool) – Forwarded to MHA. Default False.

Returns:

A tensor of shape (batch_size, time_steps, units) representing cross-attended features.

Return type:

tf.Tensor

get_config()

Returns the config of the object.

An object config is a Python dictionary (serializable) containing the information needed to re-instantiate it.

classmethod from_config(config)

Creates an operation from its config.

This method is the reverse of get_config, capable of instantiating the same operation from the config dictionary.

Note: If you override this method, you might receive a serialized dtype config, which is a dict. You can deserialize it as follows:

```python if “dtype” in config and isinstance(config[“dtype”], dict):

policy = dtype_policies.deserialize(config[“dtype”])

```

Parameters:

config – A Python dictionary, typically the output of get_config.

Returns:

An operation instance.

help(**kwargs)

my_params = CrossAttention(units, num_heads)