from nengo.builder import Builder, Signal
from nengo.builder.operator import Reset, SimPyFunc
from nengo.exceptions import BuildError
from nengo.node import Node
from nengo.processes import Process
from nengo.rc import rc
from nengo.utils.numpy import is_array_like
[docs]@Builder.register(Node)
def build_node(model, node):
"""Builds a `.Node` object into a model.
The node build function is relatively simple. It involves creating input
and output signals, and connecting them with an `.Operator` that depends
on the type of ``node.output``.
Parameters
----------
model : Model
The model to build into.
node : Node
The node to build.
Notes
-----
Sets ``model.params[node]`` to ``None``.
"""
# input signal
if not is_array_like(node.output) and node.size_in > 0:
sig_in = Signal(shape=node.size_in, name="%s.in" % node)
model.add_op(Reset(sig_in))
else:
sig_in = None
# Provide output
if node.output is None:
sig_out = sig_in
elif isinstance(node.output, Process):
sig_out = Signal(shape=node.size_out, name="%s.out" % node)
model.build(node.output, sig_in, sig_out, mode="set")
elif callable(node.output):
sig_out = (
Signal(shape=node.size_out, name="%s.out" % node)
if node.size_out > 0
else None
)
model.add_op(SimPyFunc(output=sig_out, fn=node.output, t=model.time, x=sig_in))
elif is_array_like(node.output):
sig_out = Signal(node.output.astype(rc.float_dtype), name="%s.out" % node)
else:
raise BuildError("Invalid node output type %r" % type(node.output).__name__)
model.sig[node]["in"] = sig_in
model.sig[node]["out"] = sig_out
model.params[node] = None
