gamspy#

Marks the right-hand side of an assignment as a sparse assignment.

A sparse assignment ($= in GAMS) assigns to a tuple of the left-hand side only if the right-hand side evaluates to a non-zero value. Tuples for which the right-hand side is zero are left untouched. Therefore, p[i] = sparse(rhs) is equivalent to p[i].where[rhs] = rhs but the right-hand side is evaluated only once. This can be significantly faster if the right-hand side is expensive to evaluate, e.g. a Sum.

Note that the right-hand side is always evaluated, so unlike a condition on the left-hand side, a sparse assignment does not protect against undefined arithmetic such as a division by zero.

Parameters:

rhsExpression | Operation | Condition | MathOp | Parameter | ImplicitParameter | ImplicitSet | Card | Ord | Number | int | float | bool | str: Right-hand side of the assignment.

Returns:

SparseAssignment

Examples

>>> import gamspy as gp
>>> m = gp.Container()
>>> i = gp.Set(m, "i", records=["i1", "i2", "i3"])
>>> d1 = gp.Parameter(m, "d1", domain=i, records=[("i1", 1), ("i2", 1), ("i3", 1)])
>>> d2 = gp.Parameter(m, "d2", domain=i, records=[("i2", -2)])
>>> d3 = gp.Parameter(m, "d3", domain=i)
>>> d3[i] = d1[i]
>>> d3[i] = gp.sparse(d2[i])
>>> d3.records.values.tolist()
[['i1', 1.0], ['i2', -2.0], ['i3', 1.0]]
>>> d3.getAssignment()
'd3(i) $= d2(i);'

gamspy.set_options(options: dict[Literal['GAMS_SYSDIR', 'LICENSE_PATH', 'VALIDATION', 'DOMAIN_VALIDATION', 'SOLVER_VALIDATION', 'SOLVER_OPTION_VALIDATION', 'MAP_SPECIAL_VALUES', 'ASSUME_VARIABLE_SUFFIX', 'USE_PY_VAR_NAME', 'DROP_DOMAIN_VIOLATIONS', 'ALLOW_AMBIGUOUS_EQUATIONS', 'STRICT_POWER_OPERATOR'], Any]) → None[source]#

Sets the given configuration options.

Parameters:

optionsdict[str, Any]: Option names mapped to their new values.

Raises:

ValidationError: In case the given options are not in dict type or in case an option name is not recognized.

Examples

>>> import gamspy as gp
>>> gp.set_options({"DOMAIN_VALIDATION": 1})

gamspy.get_option(name: str) → Any[source]#

Returns the requested option.

Parameters:

namestr: Option name.

Returns:

Any: The value of the option.

Raises:

KeyError: In case the option is not set.

Examples

>>> import gamspy as gp
>>> gp.set_options({"DOMAIN_VALIDATION": 0})
>>> gp.get_option("DOMAIN_VALIDATION")
0
>>> gp.set_options({"DOMAIN_VALIDATION": 1})

gamspy.serialize(container: Container, path: str) → None[source]#

Serializes the given Container into a zip file.

Parameters:

containerContainer: Container to be serialized.
pathstr: Path to the zip file.

Examples

>>> import gamspy as gp
>>> m = gp.Container()
>>> i = gp.Set(m, "i", records=range(3))
>>> gp.serialize(m, "serialization_path.zip")

gamspy.deserialize(path: str) → Container[source]#

Deserializes the given zip file into a Container.

Parameters:

pathstr: Path to the zip file.

Returns:

Container: Deserialized Container.

Raises:

ValidationError: In case the given path is not a zip file.

Examples

>>> import gamspy as gp
>>> m = gp.Container()
>>> i = gp.Set(m, "i", records=["i1"])
>>> m.serialize("model.zip")
>>> m2 = gp.deserialize("model.zip")
>>> print(m2["i"].toList())
['i1']