ScalarConstraint

(class from pyomo.core.base.constraint)

class pyomo.core.base.constraint.ScalarConstraint(*args, **kwds)[source]

Bases: ConstraintData, Constraint

ScalarConstraint is the implementation representing a single, non-indexed constraint.

__init__(*args, **kwds)[source]

Methods

`__init__`(args, *kwds)
`activate`()	Set the active attribute to True
`add`(index, expr)	Add a constraint with a given index.
`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])	Construct the expression(s) for this constraint.
`deactivate`()	Set the active attribute to False
`dim`()	Return the dimension of the index
`display`([prefix, ostream])	Print component state information
`get_suffix_value`(suffix_or_name[, default])	Get the suffix value for this component data
`get_value`()	Get the expression on this constraint.
`getname`([fully_qualified, name_buffer, ...])	Return a string with the component name and index
`has_lb`()	Returns `False` when the lower bound is `None` or negative infinity
`has_ub`()	Returns `False` when the upper bound is `None` or positive infinity
`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_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
`lslack`()	Returns the value of f(x)-L for constraints of the form:
`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.
`pprint`([ostream, verbose, prefix])	Print component information
`reconstruct`([data])	REMOVED: reconstruct() was removed in Pyomo 6.0.
`root_block`()	Return self.model()
`set_suffix_value`(suffix_or_name, value[, expand])	Set the suffix value for this component data
`set_value`(expr)	Set the expression on this constraint.
`slack`()	Returns the smaller of lslack and uslack values
`to_bounded_expression`([evaluate_bounds])	Convert this constraint to a tuple of 3 expressions (lb, body, ub)
`to_dense_data`()	TODO
`type`()	DEPRECATED.
`uslack`()	Returns the value of U-f(x) for constraints of the form:
`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

`active`	Return the active attribute
`body`	The body (variable portion) of a constraint expression.
`ctype`	Return the class type for this component
`equality`	True if this is an equality constraint.
`expr`	Return the expression associated with this constraint.
`lb`	the value of the lower bound of a constraint expression.
`local_name`	Get the component name only within the context of the immediate parent container.
`lower`	The lower bound of a constraint expression.
`name`	Get the fully qualified component name.
`strict_lower`	True if this constraint has a strict lower bound.
`strict_upper`	True if this constraint has a strict upper bound.
`ub`	the value of the upper bound of a constraint expression.
`upper`	Access the upper bound of a constraint expression.

Member Documentation

activate(): Set the active attribute to True

add(index, expr)[source]: Add a constraint with a given index.

clear()[source]: 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): Construct the expression(s) for this constraint.

deactivate(): Set the active attribute to False

dim(): Return the dimension of the index

display(prefix='', ostream=None)

Print component state information

This duplicates logic in Component.pprint()

get_suffix_value(suffix_or_name, default=None): Get the suffix value for this component data

get_value(): Get the expression on this constraint.

getname(fully_qualified=False, name_buffer=None, relative_to=None): Return a string with the component name and index

has_lb(): Returns False when the lower bound is None or negative infinity

has_ub(): Returns False when the upper bound is None or positive infinity

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_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()).

lslack()

Returns the value of f(x)-L for constraints of the form:: L <= f(x) (<= U) (U >=) f(x) >= L

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.

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_suffix_value(suffix_or_name, value, expand=True): Set the suffix value for this component data

set_value(expr)[source]: Set the expression on this constraint.

slack(): Returns the smaller of lslack and uslack values

to_bounded_expression(evaluate_bounds=False)

Convert this constraint to a tuple of 3 expressions (lb, body, ub)

This method “standardizes” the expression into a 3-tuple of expressions: (lower_bound, body, upper_bound). Upon conversion, lower_bound and upper_bound are guaranteed to be None, numeric constants, or fixed (not necessarily constant) expressions.

Note

As this method operates on the current state of the expression, any required expression manipulations (and by extension, the result) can change after fixing / unfixing Var objects.

Parameters:: evaluate_bounds (bool) – If True, then the lower and upper bounds will be evaluated to a finite numeric constant or None.
Raises:: ValueError – Raised if the expression cannot be mapped to this: form (i.e., RangedExpression constraints with variable lower or upper bounds.

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.

uslack()

Returns the value of U-f(x) for constraints of the form:: (L <=) f(x) <= U U >= f(x) (>= L)

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 body: The body (variable portion) of a constraint expression.

property ctype: Return the class type for this component

property equality

True if this is an equality constraint.

Type:: bool

property expr: Return the expression associated with this constraint.

property lb

the value of the lower bound of a constraint expression.

Type:: float

property local_name: Get the component name only within the context of the immediate parent container.

property lower

The lower bound of a constraint expression.

This is the fixed lower bound of a Constraint as a Pyomo expression. This may contain potentially variable terms that are currently fixed. If there is no lower bound, this will return None.

property name: Get the fully qualified component name.

property strict_lower

True if this constraint has a strict lower bound.

Type:: bool

property strict_upper

True if this constraint has a strict upper bound.

Type:: bool

property ub

the value of the upper bound of a constraint expression.

Type:: float

property upper

Access the upper bound of a constraint expression.

This is the fixed upper bound of a Constraint as a Pyomo expression. This may contain potentially variable terms that are currently fixed. If there is no upper bound, this will return None.