#
# GAMS - General Algebraic Modeling System Python API
#
# Copyright (c) 2023 GAMS Development Corp. <support@gams.com>
# Copyright (c) 2023 GAMS Software GmbH <support@gams.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
from __future__ import annotations
from enum import Enum
from typing import Any
from typing import List
from typing import Optional
from typing import TYPE_CHECKING
from typing import Union
import gams.transfer as gt
import pandas as pd
import gamspy as gp
import gamspy._algebra.condition as condition
import gamspy._algebra.expression as expression
import gamspy._algebra.operable as operable
import gamspy._symbols.implicits as implicits
import gamspy.utils as utils
from gamspy._symbols.symbol import Symbol
if TYPE_CHECKING:
from gamspy import Set, Container
[docs]class VariableType(Enum):
BINARY = "binary"
INTEGER = "integer"
POSITIVE = "positive"
NEGATIVE = "negative"
FREE = "free"
SOS1 = "sos1"
SOS2 = "sos2"
SEMICONT = "semicont"
SEMIINT = "semiint"
@classmethod
def values(cls):
return list(cls._value2member_map_.keys())
def __str__(self) -> str:
return self.value
[docs]class Variable(gt.Variable, operable.Operable, Symbol):
"""
Represents a variable symbol in GAMS.
https://www.gams.com/latest/docs/UG_Variables.html
Parameters
----------
container : Container
name : str
type : str, optional
domain : list, optional
records : DataFrame, optional
domain_forwarding : bool, optional
description : str, optional
Examples
--------
>>> import gamspy as gp
>>> m = gp.Container()
>>> i = gp.Set(m, "i", records=['i1','i2'])
>>> v = gp.Variable(m, "a", domain=[i])
"""
def __new__(
cls,
container: Container,
name: str,
type: str = "free",
domain: Optional[List[Union[str, Set]]] = None,
records: Optional[Any] = None,
domain_forwarding: bool = False,
description: str = "",
uels_on_axes: bool = False,
):
if not isinstance(container, gp.Container):
raise TypeError(
f"Container must of type `Container` but found {container}"
)
if not isinstance(name, str):
raise TypeError(f"Name must of type `str` but found {type(name)}")
try:
symbol = container[name]
if isinstance(symbol, cls):
return symbol
else:
raise TypeError(
f"Cannot overwrite symbol `{symbol.name}` in container"
" because it is not a Variable object)"
)
except KeyError:
return object.__new__(cls)
def __init__(
self,
container: Container,
name: str,
type: str = "free",
domain: Optional[List[Union[str, Set]]] = None,
records: Optional[Any] = None,
domain_forwarding: bool = False,
description: str = "",
uels_on_axes: bool = False,
):
type = cast_type(type)
# enable load on demand
self._is_dirty = False
# allow freezing
self._is_frozen = False
# check if the name is a reserved word
name = utils._reserved_check(name)
super().__init__(
container,
name,
type,
domain,
records,
domain_forwarding,
description,
uels_on_axes,
)
self._container_check(self.domain)
# allow conditions
self.where = condition.Condition(self)
# add statement
self.container._add_statement(self)
# create attributes
self._l, self._m, self._lo, self._up, self._s = self._init_attributes()
self._fx = self._create_attr("fx")
self._prior = self._create_attr("prior")
self._stage = self._create_attr("stage")
def __getitem__(
self, indices: Union[tuple, str]
) -> implicits.ImplicitVariable:
domain = self.domain if indices == ... else utils._to_list(indices)
return implicits.ImplicitVariable(self, name=self.name, domain=domain)
def __neg__(self):
return implicits.ImplicitVariable(
self, name=f"-{self.name}", domain=self.domain
)
def __eq__(self, other): # type: ignore
return expression.Expression(self, "=e=", other)
def _init_attributes(self):
level = self._create_attr("l")
marginal = self._create_attr("m")
lower = self._create_attr("lo")
upper = self._create_attr("up")
scale = self._create_attr("scale")
return level, marginal, lower, upper, scale
def _create_attr(self, attr_name):
domain = self.domain
return implicits.ImplicitParameter(
self,
name=f"{self.name}.{attr_name}",
records=self.records,
domain=domain,
)
@property
def l(self): # noqa: E741,E743
"""
Level
Returns
-------
ImplicitParameter
"""
return self._l
@property
def m(self):
"""
Marginal
Returns
-------
ImplicitParameter
"""
return self._m
@property
def lo(self):
"""
Lower bound
Returns
-------
ImplicitParameter
"""
return self._lo
@property
def up(self):
"""
Upper bound
Returns
-------
ImplicitParameter
"""
return self._up
@property
def scale(self):
"""
Scale
Returns
-------
ImplicitParameter
"""
return self._s
@property
def fx(self):
"""
Fx
Returns
-------
ImplicitParameter
"""
return self._fx
@property
def prior(self):
"""
Prior
Returns
-------
ImplicitParameter
"""
return self._prior
@property
def stage(self):
"""
Stage
Returns
-------
ImplicitParameter
"""
return self._stage
@property
def records(self):
"""
Records of the Variable
Returns
-------
DataFrame
"""
if not self._is_dirty:
return self._records
self.container._run(is_implicit=True)
return self._records
@records.setter
def records(self, records):
if records is not None:
if not isinstance(records, pd.DataFrame):
raise TypeError("Symbol 'records' must be type DataFrame")
# set records
self._records = records
self._requires_state_check = True
self.modified = True
self.container._requires_state_check = True
self.container.modified = True
if self._records is not None:
if self.domain_forwarding: # pragma: no cover
self._domainForwarding()
# reset state check flags for all symbols in the container
for _, symbol in self.container.data.items():
symbol._requires_state_check = True
[docs] def gamsRepr(self) -> str:
"""
Representation of this Variable in GAMS language.
Returns
-------
str
"""
return self.name
def _get_domain_str(self):
set_strs = []
for set in self.domain:
if isinstance(set, (gt.Set, gt.Alias, implicits.ImplicitSet)):
set_strs.append(set.gamsRepr())
elif isinstance(set, str):
set_strs.append("*")
return "(" + ",".join(set_strs) + ")"
[docs] def getStatement(self) -> str:
"""
Statement of the Variable definition
Returns
-------
str
"""
output = self.type + " "
statement_name = self.name
if self.domain:
statement_name += self._get_domain_str()
output += f"Variable {statement_name}"
if self.description:
output += ' "' + self.description + '"'
output += ";"
return output
def cast_type(type: Union[str, VariableType]) -> str:
if isinstance(type, str) and type.lower() not in VariableType.values():
raise ValueError(
f"Allowed variable types: {VariableType.values()} but"
f" found {type}."
)
if isinstance(type, VariableType):
type = type.value
return type.lower()
