Bases: StreamBasedExpressionVisitor
Walker to calculate bounds on an expression, from leaf to root, with
caching of terminal node bounds (Vars and Expressions)
NOTE: If anything changes on the model (e.g., Var bounds, fixing, mutable
Param values, etc), then you need to either create a new instance of this
walker, or clear self.leaf_bounds!
- Parameters:
leaf_bounds (ComponentMap in which to cache bounds at leaves of the expression) – tree
feasibility_tol (float, feasibility tolerance for interval arithmetic) – calculations
use_fixed_var_values_as_bounds (bool, whether or not to use the values of) – fixed Vars as the upper and lower bounds for those Vars or to instead
ignore fixed status and use the bounds. Set to ‘True’ if you do not
anticipate the fixed status of Variables to change for the duration that
the computed bounds should be valid.
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__init__(leaf_bounds=None, feasibility_tol=1e-08, use_fixed_var_values_as_bounds=False)[source]
Methods
__init__([leaf_bounds, feasibility_tol, ...])
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beforeChild(node, child, child_idx)
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exitNode(node, data)
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initializeWalker(expr)
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walk_expression(expr)
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Walk an expression, calling registered callbacks. |
walk_expression_nonrecursive(expr)
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Nonrecursively walk an expression, calling registered callbacks. |
Attributes
Member Documentation
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walk_expression(expr)
Walk an expression, calling registered callbacks.
This is the standard interface for running the visitor. It
defaults to using an efficient recursive implementation of the
visitor, falling back on walk_expression_nonrecursive()
if the recursion stack gets too deep.
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walk_expression_nonrecursive(expr)
Nonrecursively walk an expression, calling registered callbacks.
This routine is safer than the recursive walkers for deep (or
unbalanced) trees. It is, however, slightly slower than the
recursive implementations.