Param

(class from pyomo.core.base.param)

class pyomo.core.base.param.Param(*args, **kwds)

Bases: IndexedComponent, IndexedComponent_NDArrayMixin

A parameter value, which may be defined over an index.

Constructor Arguments:

domain

A set that defines the type of values that each parameter must be.

within

A set that defines the type of values that each parameter must be.

validate

A rule for validating this parameter w.r.t. data that exists in the model

default

A scalar, rule, or dictionary that defines default values for this parameter

initialize

A dictionary or rule for setting up this parameter with existing model data

unit: pyomo unit expression

An expression containing the units for the parameter

mutable: boolean

Flag indicating if the value of the parameter may change between calls to a solver. Defaults to False

name

Name for this component.

doc

Text describing this component.

__init__(*args, **kwd)

Methods

__init__(*args, **kwd)
clear()	Clear the data in this component
clear_suffix_value(suffix_or_name[, expand])	Clear the suffix value for this component data
cname(*args, **kwds)	DEPRECATED.
construct([data])	Initialize this component.
default()	Return the value of the parameter default.
dim()	Return the dimension of the index
display([ostream, verbose, prefix])
extract_values()	A utility to extract all index-value pairs defined for this parameter, returned as a dictionary.
extract_values_sparse()	A utility to extract all index-value pairs defined with non-default values, returned as a dictionary.
get_suffix_value(suffix_or_name[, default])	Get the suffix value for this component data
get_units()	Return the units for this ParamData
getname([fully_qualified, name_buffer, ...])	Returns the component name associated with this object.
id_index_map()	Return an dictionary id->index for all ComponentData instances.
index_set()	Return the index set
is_component_type()	Return True if this class is a Pyomo component
is_constructed()	Return True if this class has been constructed
is_expression_type([expression_system])	Return True if this numeric value is an expression
is_indexed()	Return true if this component is indexed
is_logical_type()	Return True if this class is a Pyomo Boolean object.
is_named_expression_type()	Return True if this numeric value is a named expression
is_numeric_type()	Return True if this class is a Pyomo numeric object
is_parameter_type()	Return False unless this class is a parameter object
is_reference()	Return True if this component is a reference, where "reference" is interpreted as any component that does not own its own data.
is_variable_type()	Return False unless this class is a variable object
items([sort, ordered])	Return an iterator of (index,data) component data tuples
iteritems()	DEPRECATED.
iterkeys()	DEPRECATED.
itervalues()	DEPRECATED.
keys([sort, ordered])	Return an iterator over the component data keys
model()	Returns the model associated with this object.
parent_block()	Returns the parent of this object.
parent_component()	Returns the component associated with this object.
pprint([ostream, verbose, prefix])	Print component information
reconstruct([data])	REMOVED: reconstruct() was removed in Pyomo 6.0.
root_block()	Return self.model()
set_default(val)	Perform error checks and then set the default value for this parameter.
set_suffix_value(suffix_or_name, value[, expand])	Set the suffix value for this component data
set_value(value)	Set the value of a scalar component.
sparse_items()	Return a list (index,data) tuples for defined parameters
sparse_iteritems()	Return an iterator of (index,data) tuples for defined parameters
sparse_iterkeys()	Return an iterator for the keys in the defined parameters
sparse_itervalues()	Return an iterator for the defined param data objects
sparse_keys()	Return a list of keys in the defined parameters
sparse_values()	Return a list of the defined param data objects
store_values(new_values[, check])	A utility to update a Param with a dictionary or scalar.
to_dense_data()	TODO
type()	DEPRECATED.
valid_model_component()	Return True if this can be used as a model component.
values([sort, ordered])	Return an iterator of the component data objects

Attributes

DefaultMutable
active	Return the active attribute
ctype	Return the class type for this component
local_name	Get the component name only within the context of the immediate parent container.
mutable
name	Get the fully qualified component name.

Member Documentation

class NoValue

Bases: object

A dummy type that is pickle-safe that we can use as the default value for Params to indicate that no valid value is present.

clear()

Clear the data in this component

clear_suffix_value(suffix_or_name, expand=True)

Clear the suffix value for this component data

cname(*args, **kwds)

DEPRECATED.

Deprecated since version 5.0: The cname() method has been renamed to getname(). The preferred method of obtaining a component name is to use the .name property, which returns the fully qualified component name. The .local_name property will return the component name only within the context of the immediate parent container.

construct(data=None)

Initialize this component.

A parameter is constructed using the initial data or the data loaded from an external source. We first set all the values based on self._rule, and then allow the data dictionary to overwrite anything.

Note that we allow an undefined Param value to be constructed. We throw an exception if a user tries to use an uninitialized Param.

default()

Return the value of the parameter default.

Possible values:

Param.NoValue

No default value is provided.

Numeric

A constant value that is the default value for all undefined parameters.

Function

f(model, i) returns the value for the default value for parameter i

dim()

Return the dimension of the index

extract_values()

A utility to extract all index-value pairs defined for this parameter, returned as a dictionary.

This method is useful in contexts where key iteration and repeated __getitem__ calls are too expensive to extract the contents of a parameter.

extract_values_sparse()

A utility to extract all index-value pairs defined with non-default values, returned as a dictionary.

This method is useful in contexts where key iteration and repeated __getitem__ calls are too expensive to extract the contents of a parameter.

get_suffix_value(suffix_or_name, default=None)

Get the suffix value for this component data

get_units()

Return the units for this ParamData

getname(fully_qualified=False, name_buffer=None, relative_to=None)

Returns the component name associated with this object.

Parameters:

• fully_qualified (bool) – Generate full name from nested block names

• relative_to (Block) – Generate fully_qualified names relative to the specified block.

id_index_map()

Return an dictionary id->index for all ComponentData instances.

index_set()

Return the index set

is_component_type()

Return True if this class is a Pyomo component

is_constructed()

Return True if this class has been constructed

is_expression_type(expression_system=None)

Return True if this numeric value is an expression

is_indexed()

Return true if this component is indexed

is_logical_type()

Return True if this class is a Pyomo Boolean object.

Boolean objects include constants, variables, or logical expressions.

is_named_expression_type()

Return True if this numeric value is a named expression

is_numeric_type()

Return True if this class is a Pyomo numeric object

is_parameter_type()

Return False unless this class is a parameter object

is_reference()

Return True if this component is a reference, where “reference” is interpreted as any component that does not own its own data.

is_variable_type()

Return False unless this class is a variable object

items(sort=<SortComponents.UNSORTED: 0>, ordered=NOTSET)

Return an iterator of (index,data) component data tuples

Parameters:

• sort (bool or SortComponents) – Iterate over the declared component items in a specified sorted order. See SortComponents for valid options and descriptions.

• ordered (bool) – DEPRECATED: Please use sort=SortComponents.ORDERED_INDICES. If True, then the items are returned in a deterministic order (using the underlying set’s ordered_iter().

iteritems()

DEPRECATED.

Return a list (index,data) tuples from the dictionary

Deprecated since version 6.0: The iteritems method is deprecated. Use dict.items().

iterkeys()

DEPRECATED.

Return a list of keys in the dictionary

Deprecated since version 6.0: The iterkeys method is deprecated. Use dict.keys().

itervalues()

DEPRECATED.

Return a list of the component data objects in the dictionary

Deprecated since version 6.0: The itervalues method is deprecated. Use dict.values().

keys(sort=<SortComponents.UNSORTED: 0>, ordered=NOTSET)

Return an iterator over the component data keys

This method sets the ordering of component data objects within this IndexedComponent container. For consistency, __init__(), values(), and items() all leverage this method to ensure consistent ordering.

Parameters:

• sort (bool or SortComponents) – Iterate over the declared component keys in a specified sorted order. See SortComponents for valid options and descriptions.

• ordered (bool) – DEPRECATED: Please use sort=SortComponents.ORDERED_INDICES. If True, then the keys are returned in a deterministic order (using the underlying set’s ordered_iter()).

model()

Returns the model associated with this object.

parent_block()

Returns the parent of this object.

parent_component()

Returns the component associated with this object.

pprint(ostream=None, verbose=False, prefix='')

Print component information

reconstruct(data=None)

REMOVED: reconstruct() was removed in Pyomo 6.0.

Re-constructing model components was fragile and did not correctly update instances of the component used in other components or contexts (this was particularly problemmatic for Var, Param, and Set). Users who wish to reproduce the old behavior of reconstruct(), are comfortable manipulating non-public interfaces, and who take the time to verify that the correct thing happens to their model can approximate the old behavior of reconstruct with:

component.clear() component._constructed = False component.construct()

root_block()

Return self.model()

set_default(val)

Perform error checks and then set the default value for this parameter.

NOTE: this test will not validate the value of function return values.

set_suffix_value(suffix_or_name, value, expand=True)

Set the suffix value for this component data

set_value(value)

Set the value of a scalar component.

sparse_items()

Return a list (index,data) tuples for defined parameters

sparse_iteritems()

Return an iterator of (index,data) tuples for defined parameters

sparse_iterkeys()

Return an iterator for the keys in the defined parameters

sparse_itervalues()

Return an iterator for the defined param data objects

sparse_keys()

Return a list of keys in the defined parameters

sparse_values()

Return a list of the defined param data objects

store_values(new_values, check=True)

A utility to update a Param with a dictionary or scalar.

If check=True, then both the index and value are checked through the __getitem__ method. Using check=False should only be used by developers!

to_dense_data()

TODO

type()

DEPRECATED.

Return the class type for this component

Deprecated since version 5.7: Component.type() method has been replaced by the .ctype property.

valid_model_component()

Return True if this can be used as a model component.

values(sort=<SortComponents.UNSORTED: 0>, ordered=NOTSET)

Return an iterator of the component data objects

Parameters:

• sort (bool or SortComponents) – Iterate over the declared component values in a specified sorted order. See SortComponents for valid options and descriptions.

• ordered (bool) – DEPRECATED: Please use sort=SortComponents.ORDERED_INDICES. If True, then the values are returned in a deterministic order (using the underlying set’s ordered_iter().

property active

Return the active attribute

property ctype

Return the class type for this component

property local_name

Get the component name only within the context of the immediate parent container.

property name

Get the fully qualified component name.