symlayer

class symflow.SymLayer(*args, **kwargs)

Create a keras layer based on sympy expressions.

Args:

exprs: List of sympy expressions that define the operations that need to be performed by the Layer. arguments: List of sympy symbols that are required to fulfill the above sympy expressions. *args: Arguments passed on to tf.keras.layers.Layer initialization. *kwargs: Keyword arguments passed on to tf.keras.layers.Layer initialization.

Attributes:

exprs: List of sympy expressions that define the operations that are performed by the Layer. args: List of sympy symbols that correspond to the input of the layer’s inputs argument in the call method.

Examples:

todo

build(input_shape, *args, **kwargs)

Creates the variables of the layer (optional, for subclass implementers).

This is a method that implementers of subclasses of Layer or Model can override if they need a state-creation step in-between layer instantiation and layer call.

This is typically used to create the weights of Layer subclasses.

Args:

input_shape: Instance of TensorShape, or list of instances of

TensorShape if the layer expects a list of inputs (one instance per input).

call(inputs)

This is where the layer’s logic lives.

Note here that call() method in tf.keras is little bit different from keras API. In keras API, you can pass support masking for layers as additional arguments. Whereas tf.keras has compute_mask() method to support masking.

Args:

inputs: Input tensor, or dict/list/tuple of input tensors.

The first positional inputs argument is subject to special rules: - inputs must be explicitly passed. A layer cannot have zero

arguments, and inputs cannot be provided via the default value of a keyword argument.

• NumPy array or Python scalar values in inputs get cast as tensors.

• Keras mask metadata is only collected from inputs.

• Layers are built (build(input_shape) method) using shape info from inputs only.

• input_spec compatibility is only checked against inputs.

• Mixed precision input casting is only applied to inputs. If a layer has tensor arguments in *args or **kwargs, their casting behavior in mixed precision should be handled manually.

• The SavedModel input specification is generated using inputs only.

• Integration with various ecosystem packages like TFMOT, TFLite, TF.js, etc is only supported for inputs and not for tensors in positional and keyword arguments.

*args: Additional positional arguments. May contain tensors, although

this is not recommended, for the reasons above.

**kwargs: Additional keyword arguments. May contain tensors, although

this is not recommended, for the reasons above. The following optional keyword arguments are reserved: - training: Boolean scalar tensor of Python boolean indicating

whether the call is meant for training or inference.

• mask: Boolean input mask. If the layer’s call() method takes a mask argument, its default value will be set to the mask generated for inputs by the previous layer (if input did come from a layer that generated a corresponding mask, i.e. if it came from a Keras layer with masking support).

Returns:

A tensor or list/tuple of tensors.