picos.modeling.footprint¶

Optimization problem description classes.

This module implements a footprint of a single problem, storing number and types of expressions and constraints, and the specification of a problem class.

Outline¶

Classes¶

`Footprint`	Statistics on an optimization problem.
`Specification`	Representation of a mathematical class of optimization problems.

Classes¶

Footprint¶

class picos.modeling.footprint.Footprint(recordsOrDict)[source]¶

Bases: picos.containers.RecordTree

Statistics on an optimization problem.

Subtree comparison (<<) can be used to check if a specific problem represented by a Footprint instance is contained in a problem class represented by a Specification instance.

__init__(recordsOrDict)[source]¶

Construct a Footprint from raw data.

See picos.containers.RecordTree.__init__. The addValues argument is fixed; only variable and constraint paths are added.

classmethod from_problem(problem)[source]¶: Create a footprint from a problem instance.

classmethod from_types(obj_dir, obj_func, vars=[], cons=[], nd_opts={})[source]¶

Create a footprint from collections of detailed types.

Parameters

obj_dir (str) – Objective direction.
obj_func – Detailed objective function type.
nd_opts (list(str)) – A dictionary mapping option names to nondefault values.

Parm list(tuple) vars

A list of pairs of detailed variable type and occurence count.

Parm list(tuple) cons

A list of pairs of detailed constraint type and occurence count.

updated(recordsOrDict)[source]¶

Override updated.

This method, just like __init__, does not take the additional addValues argument.

with_extra_options(**extra_options)[source]¶: Return a copy with additional solution search options applied.

property constraints¶: A dictionary mapping detailed constraint types to their quantity.

property continuous¶: Whether no integral variable type is present.

property cost¶

A very rough measure on how expensive solving such a problem is.

This is logarithmic in the estimated size of the constraint matrix.

property direction¶: Objective function optimization direction.

property integer¶: Whether an integral variable type is present.

property nonconvex_quadratic_objective¶: Whether the problem has a nonconvex quadratic objective.

property nondefault_options¶: A dictionary mapping option names to their nondefault values.

Warning

This property is cached for performance reasons, do not modify any mutable option value (make a deep copy instead)!

property objective¶: Detailed type of the objective function.

property options¶: An Options object.

Warning

This property is cached for performance reasons, do not modify the returned object (make a copy instead)!

property size¶: Return the estimated size of the (dense) scalar constraint matrix.

property variables¶: A dictionary mapping detailed variable types to their quantity.

Specification¶

class picos.modeling.footprint.Specification(recordsOrDict)[source]¶

Bases: picos.containers.RecordTree

Representation of a mathematical class of optimization problems.

Subtree comparison (<<) can be used to check if a specific problem represented by a Footprint instance is contained in a problem class represented by a Specification instance.

__init__(recordsOrDict)[source]¶

Construct a Specification from raw data.

See picos.containers.RecordTree.__init__.

classmethod compile(directions=(), objectives=(), variables=(), constraints=(), nondefault_options=<class 'picos.containers.RecordTree.ALL'>)[source]¶: Create a specification from the given features.