"""Definition of the Demux Component."""
import numpy as np
from openmdao.core.explicitcomponent import ExplicitComponent
from openmdao.utils.om_warnings import warn_deprecation
from openmdao.utils.array_utils import shape_to_len
[docs]class DemuxComp(ExplicitComponent):
"""
Demux one or more inputs along a given axis.
Parameters
----------
**kwargs : dict
Arguments to be passed to the component initialization method.
Attributes
----------
_vars : dict
Container mapping name of variables to be demuxed with additional data.
_output_names : dict
Container mapping name of variables to be demuxed with associated outputs.
"""
[docs] def __init__(self, **kwargs):
"""
Instantiate DemuxComp and populate private members.
"""
super().__init__(**kwargs)
self._vars = {}
self._output_names = {}
self._no_check_partials = True
warn_deprecation("DemuxComp is being deprecated. This same functionality can be achieved "
"directly in the connect/promotes indices arg using om.slicer.")
[docs] def initialize(self):
"""
Declare options.
"""
self.options.declare('vec_size', types=int, default=2,
desc='The number of elements to be extracted from each input.')
[docs] def add_var(self, name, val=1.0, shape=None, units=None, desc='', axis=0):
"""
Add an input variable to be demuxed, and all associated output variables.
Parameters
----------
name : str
Name of the variable in this component's namespace.
val : float or list or tuple or ndarray or Iterable
The initial value of the variable being added in user-defined units.
Default is 1.0.
shape : int or tuple or list or None
Shape of this variable, only required if val is not an array. Default is None.
units : str or None
Units in which this input variable will be provided to the component
during execution. Default is None, which means it is unitless.
desc : str
Description of the variable.
axis : int
The axis along which the elements will be selected. Note the axis must have length
vec_size, otherwise a RuntimeError is raised at setup.
"""
self._vars[name] = {'val': val, 'shape': shape, 'units': units, 'desc': desc, 'axis': axis}
opts = self.options
vec_size = opts['vec_size']
# for var, options in self._vars.items():
options = self._vars[name]
kwgs = dict(options)
shape = options['shape']
size = shape_to_len(shape)
axis = kwgs.pop('axis')
if axis >= len(shape):
raise RuntimeError("{}: Invalid axis ({}) for variable '{}' of "
"shape {}".format(self.msginfo, axis, name, shape))
if shape[axis] != vec_size:
raise RuntimeError("{}: Variable '{}' cannot be demuxed along axis {}. Axis size "
"is {} but vec_size is {}.".format(self.msginfo, name, axis,
shape[axis], vec_size))
self.add_input(name, **kwgs)
template = np.reshape(np.arange(size), shape)
self._output_names[name] = []
out_shape = list(shape)
out_shape.pop(axis)
if len(out_shape) == 0:
out_shape = [1]
for i in range(vec_size):
out_name = '{0}_{1}'.format(name, i)
self._output_names[name].append(out_name)
self.add_output(name=out_name,
val=options['val'],
shape=out_shape,
units=options['units'],
desc=options['desc'])
rs = np.arange(shape_to_len(out_shape))
cs = np.atleast_1d(np.take(template, indices=i, axis=axis)).flatten()
self.declare_partials(of=out_name, wrt=name, rows=rs, cols=cs, val=1.0)
[docs] def compute(self, inputs, outputs):
"""
Demux the inputs into the appropriate outputs using numpy.take.
Parameters
----------
inputs : Vector
Unscaled, dimensional input variables read via inputs[key].
outputs : Vector
Unscaled, dimensional output variables read via outputs[key].
"""
opts = self.options
vec_size = opts['vec_size']
for var in self._vars:
ax = self._vars[var]['axis']
for i in range(vec_size):
out_name = self._output_names[var][i]
outputs[out_name] = np.reshape(np.take(inputs[var], indices=i, axis=ax),
newshape=outputs[out_name].shape)
