ScalarParam

(class from pyomo.core.base.param)

class pyomo.core.base.param.ScalarParam(*args, **kwds)[source]

Bases: ParamData, Param

__init__(*args, **kwds)[source]

Methods

`__init__`(args, *kwds)
`clear`()	Clear the data in this component
`clear_suffix_value`(suffix_or_name[, expand])	Set 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, ...])	Return a string with the component name and index
`id_index_map`()	Return an dictionary id->index for all ComponentData instances.
`index`()	Returns the index of this ComponentData instance relative to the parent component index set.
`index_set`()	Return the index set
`is_component_type`()	Return True if this class is a Pyomo component
`is_constant`()	Determine if this ScalarParam is constant (and can be eliminated)
`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_fixed`()	Returns True because this value is fixed.
`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`()	Returns True because this is a parameter object.
`is_potentially_variable`()	Return True if variables can appear in this expression
`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_relational`()	DEPRECATED.
`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`()	Return the model of the component that owns this data.
`parent_block`()	Return the parent of the component that owns this data.
`parent_component`()	Returns the component associated with this object.
`polynomial_degree`()	Return the polynomial degree of the expression.
`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[, index])	Set the value of this ParamData object, performing unit conversion and validation as necessary.
`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
`to_string`([verbose, labeler, smap, ...])	Return a string representation of the expression tree.
`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.
`value`	Return the value for this variable.

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): Set 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): Return a string with the component name and index

id_index_map(): Return an dictionary id->index for all ComponentData instances.

index(): Returns the index of this ComponentData instance relative to the parent component index set. None is returned if this instance does not have a parent component, or if - for some unknown reason - this instance does not belong to the parent component’s index set.

index_set(): Return the index set

is_component_type(): Return True if this class is a Pyomo component

is_constant()[source]

Determine if this ScalarParam is constant (and can be eliminated)

Returns False if either unconstructed or mutable, as it must be kept in expressions (as it either doesn’t have a value yet or the value can change later.

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_fixed(): Returns True because this value is fixed.

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(): Returns True because this is a parameter object.

is_potentially_variable(): Return True if variables can appear in this expression

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_relational()

DEPRECATED.

Return True if this numeric value represents a relational expression.

Deprecated since version 6.4.3: is_relational() is deprecated in favor of is_expression_type(ExpressionType.RELATIONAL)

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(): Return the model of the component that owns this data.

parent_block(): Return the parent of the component that owns this data.

parent_component(): Returns the component associated with this object.

polynomial_degree()

Return the polynomial degree of the expression.

Returns:: None

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, index=NOTSET)[source]: Set the value of this ParamData object, performing unit conversion and validation as necessary.

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

to_string(verbose=None, labeler=None, smap=None, compute_values=False)

Return a string representation of the expression tree.

Parameters:

verbose (bool) – If True, then the string representation consists of nested functions. Otherwise, the string representation is an infix algebraic equation. Defaults to False.
labeler – An object that generates string labels for non-constant in the expression tree. Defaults to None.
smap – A SymbolMap instance that stores string labels for non-constant nodes in the expression tree. Defaults to None.
compute_values (bool) – If True, then fixed expressions are evaluated and the string representation of the resulting value is returned.

Returns:

A string representation for the expression tree.

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.

property value: Return the value for this variable.