Highs

(class from pyomo.contrib.appsi.solvers.highs)

class pyomo.contrib.appsi.solvers.highs.Highs(only_child_vars=False)[source]

Bases: PersistentBase, PersistentSolver

Interface to HiGHS

__init__(only_child_vars=False)[source]

Methods

`__init__`([only_child_vars])
`add_block`(block)
`add_constraints`(cons)
`add_params`(params)
`add_sos_constraints`(cons)
`add_variables`(variables)
`available`()	Test if the solver is available on this system.
`get_duals`([cons_to_load])	Declare sign convention in docstring here.
`get_primals`([vars_to_load, solution_number])
`get_reduced_costs`([vars_to_load])
`get_slacks`([cons_to_load])
`is_persistent`()
`load_vars`([vars_to_load])	Load the solution of the primal variables into the value attribute of the variables.
`remove_block`(block)
`remove_constraints`(cons)
`remove_params`(params)
`remove_sos_constraints`(cons)
`remove_variables`(variables)
`set_instance`(model)
`set_objective`(obj)
`solve`(model[, timer])	Solve a Pyomo model.
`update`([timer])
`update_params`()
`update_variables`(variables)
`version`()

Attributes

`config`	An object for configuring solve options.
`highs_options`	A dictionary mapping solver options to values for those options.
`symbol_map`
`update_config`

Member Documentation

enum Availability(value)

Bases: IntEnum

as_integer_ratio()

Return integer ratio.

Return a pair of integers, whose ratio is exactly equal to the original int and with a positive denominator.

>>> (10).as_integer_ratio()
(10, 1)
>>> (-10).as_integer_ratio()
(-10, 1)
>>> (0).as_integer_ratio()
(0, 1)

bit_count()

Number of ones in the binary representation of the absolute value of self.

Also known as the population count.

>>> bin(13)
'0b1101'
>>> (13).bit_count()
3

bit_length()

Number of bits necessary to represent self in binary.

>>> bin(37)
'0b100101'
>>> (37).bit_length()
6

conjugate(): Returns self, the complex conjugate of any int.

classmethod from_bytes(bytes, byteorder='big', *, signed=False)

Return the integer represented by the given array of bytes.

bytes: Holds the array of bytes to convert. The argument must either support the buffer protocol or be an iterable object producing bytes. Bytes and bytearray are examples of built-in objects that support the buffer protocol.
byteorder: The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use sys.byteorder as the byte order value. Default is to use ‘big’.
signed: Indicates whether two’s complement is used to represent the integer.

to_bytes(length=1, byteorder='big', *, signed=False)

Return an array of bytes representing an integer.

length: Length of bytes object to use. An OverflowError is raised if the integer is not representable with the given number of bytes. Default is length 1.
byteorder: The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use sys.byteorder as the byte order value. Default is to use ‘big’.
signed: Determines whether two’s complement is used to represent the integer. If signed is False and a negative integer is given, an OverflowError is raised.

denominator: the denominator of a rational number in lowest terms

imag: the imaginary part of a complex number

numerator: the numerator of a rational number in lowest terms

real: the real part of a complex number

available()[source]

Test if the solver is available on this system.

Nominally, this will return True if the solver interface is valid and can be used to solve problems and False if it cannot.

Note that for licensed solvers there are a number of “levels” of available: depending on the license, the solver may be available with limitations on problem size or runtime (e.g., ‘demo’ vs. ‘community’ vs. ‘full’). In these cases, the solver may return a subclass of enum.IntEnum, with members that resolve to True if the solver is available (possibly with limitations). The Enum may also have multiple members that all resolve to False indicating the reason why the interface is not available (not found, bad license, unsupported version, etc).

Returns:: available – An enum that indicates “how available” the solver is. Note that the enum can be cast to bool, which will be True if the solver is runable at all and False otherwise.
Return type:: Solver.Availability

get_duals(cons_to_load=None)[source]

Declare sign convention in docstring here.

Parameters:: cons_to_load (list) – A list of the constraints whose duals should be loaded. If cons_to_load is None, then the duals for all constraints will be loaded.
Returns:: duals – Maps constraints to dual values
Return type:: dict

get_reduced_costs(vars_to_load=None)[source]

Parameters:: vars_to_load (list) – A list of the variables whose reduced cost should be loaded. If vars_to_load is None, then all reduced costs will be loaded.
Returns:: reduced_costs – Maps variable to reduced cost
Return type:: ComponentMap

get_slacks(cons_to_load=None)[source]

Parameters:: cons_to_load (list) – A list of the constraints whose slacks should be loaded. If cons_to_load is None, then the slacks for all constraints will be loaded.
Returns:: slacks – Maps constraints to slack values
Return type:: dict

is_persistent()

Returns:: is_persistent – True if the solver is a persistent solver.
Return type:: bool

load_vars(vars_to_load=None)[source]

Load the solution of the primal variables into the value attribute of the variables.

Parameters:: vars_to_load (list) – A list of the variables whose solution should be loaded. If vars_to_load is None, then the solution to all primal variables will be loaded.

solve(model, timer: HierarchicalTimer = None) → Results[source]

Solve a Pyomo model.

Parameters:

model (BlockData) – The Pyomo model to be solved
timer (HierarchicalTimer) – An option timer for reporting timing

Returns:

results – A results object

Return type:

Results

version()[source]

Returns:: version – A tuple representing the version
Return type:: tuple

property config: HighsConfig

An object for configuring solve options.

Returns:: An object for configuring pyomo solve options such as the time limit. These options are mostly independent of the solver.
Return type:: SolverConfig

property highs_options

A dictionary mapping solver options to values for those options. These are solver specific.

Returns:: A dictionary mapping solver options to values for those options
Return type:: dict