CompoundModel¶
-
class
astropy.modeling.
CompoundModel
(op, left, right, name=None, inverse=None)[source]¶ Bases:
astropy.modeling.Model
Base class for compound models.
While it can be used directly, the recommended way to combine models is through the model operators.
Attributes Summary
List of parameter equality constraints.
Set the fittable attribute on a compound model.
A flag indicating whether or not a custom bounding_box has been assigned to this model by a user, via assignment to
model.bounding_box
.List of parameter inequality constraints.
This property is used to indicate what units or sets of units the evaluate method expects, and returns a dictionary mapping inputs to units (or
None
if any units are accepted).Allow dimensionless input (and corresponding output).
Enforce strict units on inputs to evaluate.
The number of inputs of a model.
The number of outputs of a model.
Return the number of components in a single model, which is obviously 1.
An ordered list of parameter names.
This property is used to indicate what units or sets of units the output of evaluate should be in, and returns a dictionary mapping outputs to units (or
None
if any units are accepted).Return the names of submodels in a
CompoundModel
.Methods Summary
__call__
(self, *args, **kw)Evaluate this model using the given input(s) and the parameter values that were specified when the model was instantiated.
both_inverses_exist
(self)if both members of this compound model have inverses return True
evaluate
(self, *args, **kwargs)Evaluate the model on some input variables.
inputs_map
(self)Map the names of the inputs to this ExpressionTree to the inputs to the leaf models.
outputs_map
(self)Map the names of the outputs to this ExpressionTree to the outputs to the leaf models.
rename
(self, name)Creates a copy of this model class with a new name, inputs or outputs.
render
(self[, out, coords])Evaluate a model at fixed positions, respecting the
bounding_box
.replace_submodel
(self, name, model)Construct a new
CompoundModel
instance from an existing CompoundModel, replacing the named submodel with a new model.traverse_postorder
(self[, include_operator])Postorder traversal of the CompoundModel tree.
Attributes Documentation
-
eqcons
¶ List of parameter equality constraints.
-
fittable
¶ Set the fittable attribute on a compound model.
-
has_user_bounding_box
¶ A flag indicating whether or not a custom bounding_box has been assigned to this model by a user, via assignment to
model.bounding_box
.
-
ineqcons
¶ List of parameter inequality constraints.
-
input_units
¶ This property is used to indicate what units or sets of units the evaluate method expects, and returns a dictionary mapping inputs to units (or
None
if any units are accepted).Model sub-classes can also use function annotations in evaluate to indicate valid input units, in which case this property should not be overridden since it will return the input units based on the annotations.
-
input_units_allow_dimensionless
¶ Allow dimensionless input (and corresponding output). If this is True, input values to evaluate will gain the units specified in input_units. If this is a dictionary then it should map input name to a bool to allow dimensionless numbers for that input. Only has an effect if input_units is defined.
-
input_units_equivalencies
¶
-
input_units_strict
¶ Enforce strict units on inputs to evaluate. If this is set to True, input values to evaluate will be in the exact units specified by input_units. If the input quantities are convertible to input_units, they are converted. If this is a dictionary then it should map input name to a bool to set strict input units for that parameter.
-
isleaf
¶
-
n_inputs
¶ The number of inputs of a model.
-
n_outputs
¶ The number of outputs of a model.
-
n_submodels
¶ Return the number of components in a single model, which is obviously 1.
-
param_names
¶ An ordered list of parameter names.
-
return_units
¶ This property is used to indicate what units or sets of units the output of evaluate should be in, and returns a dictionary mapping outputs to units (or
None
if any units are accepted).Model sub-classes can also use function annotations in evaluate to indicate valid output units, in which case this property should not be overridden since it will return the return units based on the annotations.
-
submodel_names
¶ Return the names of submodels in a
CompoundModel
.
Methods Documentation
-
__call__
(self, *args, **kw)[source]¶ Evaluate this model using the given input(s) and the parameter values that were specified when the model was instantiated.
-
inputs_map
(self)[source]¶ Map the names of the inputs to this ExpressionTree to the inputs to the leaf models.
-
outputs_map
(self)[source]¶ Map the names of the outputs to this ExpressionTree to the outputs to the leaf models.
-
rename
(self, name)[source]¶ Creates a copy of this model class with a new name, inputs or outputs.
The new class is technically a subclass of the original class, so that instance and type checks will still work. For example:
>>> from astropy.modeling.models import Rotation2D >>> SkyRotation = Rotation2D.rename('SkyRotation') >>> SkyRotation <class 'astropy.modeling.core.SkyRotation'> Name: SkyRotation (Rotation2D) N_inputs: 2 N_outputs: 2 Fittable parameters: ('angle',) >>> issubclass(SkyRotation, Rotation2D) True >>> r = SkyRotation(90) >>> isinstance(r, Rotation2D) True
-
render
(self, out=None, coords=None)[source]¶ Evaluate a model at fixed positions, respecting the
bounding_box
.The key difference relative to evaluating the model directly is that this method is limited to a bounding box if the
Model.bounding_box
attribute is set.- Parameters
- out
numpy.ndarray
, optional An array that the evaluated model will be added to. If this is not given (or given as
None
), a new array will be created.- coordsarray_like, optional
An array to be used to translate from the model’s input coordinates to the
out
array. It should have the property thatself(coords)
yields the same shape asout
. Ifout
is not specified,coords
will be used to determine the shape of the returned array. If this is not provided (or None), the model will be evaluated on a grid determined byModel.bounding_box
.
- out
- Returns
- out
numpy.ndarray
The model added to
out
ifout
is notNone
, or else a new array from evaluating the model overcoords
. Ifout
andcoords
are bothNone
, the returned array is limited to theModel.bounding_box
limits. IfModel.bounding_box
isNone
,arr
orcoords
must be passed.
- out
- Raises
- ValueError
If
coords
are not given and the theModel.bounding_box
of this model is not set.
Examples
-
replace_submodel
(self, name, model)[source]¶ Construct a new
CompoundModel
instance from an existing CompoundModel, replacing the named submodel with a new model.In order to ensure that inverses and names are kept/reconstructed, it’s necessary to rebuild the CompoundModel from the replaced node all the way back to the base. The original CompoundModel is left untouched.
- Parameters
- namestr
name of submodel to be replaced
- model
Model
replacement model
-