LSExternalContext Class¶

class LSExternalContext¶

Context of an external function. External contexts can be used to query and set properties of the associated external function.

If you known the bounds of the external function or if you know it cannot return a NaN value, we recommend you to specify it as LocalSolver is then able to improve its search process. But beware! If the evaluation of the function returns an unexpected value (like a value outside of the bounds), an exception will be thrown during the search.

See:: LSExpression::getExternalContext()
Since:: 9.5

Summary¶

Functions¶
`getIntLowerBound`	Gets the lower bound of the external function.
`getIntUpperBound`	Gets the upper bound of the external function.
`getDoubleLowerBound`	Gets the lower bound of the external function.
`getDoubleUpperBound`	Gets the upper bound of the external function.
`isNanable`	Returns true if the function can return a NaN (Not a Number) value.
`setLowerBound`	Sets the lower bound of the external function.
`setLowerBound`	Sets the lower bound of the external function.
`setUpperBound`	Sets the upper bound of the external function.
`setUpperBound`	Sets the upper bound of the external function.
`setIntLowerBound`	Sets the lower bound of the external function.
`setIntUpperBound`	Sets the upper bound of the external function.
`setDoubleLowerBound`	Sets the lower bound of the external function.
`setDoubleUpperBound`	Sets the upper bound of the external function.
`setNanable`	Sets whether or not the function can return a NaN (Not a Number) value.
`enableSurrogateModeling`	Enables the surrogate modeling on the associated external function.

Functions¶

lsint LSExternalContext::getIntLowerBound() const¶

Gets the lower bound of the external function. Only allowed if the external function is an integer function. By default, this property is set to LONG_LONG_MIN.

Returns:: Lower bound of the external function.

lsint LSExternalContext::getIntUpperBound() const¶

Gets the upper bound of the external function. Only allowed if the external function is an integer function. By default, this property is set to LONG_LONG_MAX.

Returns:: Upper bound of the external function.

lsdouble LSExternalContext::getDoubleLowerBound() const¶

Gets the lower bound of the external function. Only allowed if the external function is a double function. By default, this property is set to -INFINITY.

Returns:: Lower bound of the external function.

lsdouble LSExternalContext::getDoubleUpperBound() const¶

Gets the upper bound of the external function. Only allowed if the external function is a double function. By default, this property is set to INFINITY.

Returns:: Upper bound of the external function.

bool LSExternalContext::isNanable() const¶

Returns true if the function can return a NaN (Not a Number) value. Only allowed if the external function is a double function. By default this property is set to true.

Returns:: True if the function can return a NaN value.

void LSExternalContext::setLowerBound(lsint lowerBound)¶

Sets the lower bound of the external function. Only allowed if the external function is an integer function. If it is an array function, the bound will apply to all elements of the array. Only allowed in state S_Modeling. This method has the same behaviour as LSExternalContext::setIntLowerBound()

Parameters:: lowerBound – Lower bound of the function.

void LSExternalContext::setLowerBound(lsdouble lowerBound)¶

Sets the lower bound of the external function. Only allowed if the external function is a double function. If it is an array function, the bound will apply to all elements of the array. Only allowed in state S_Modeling. This method has the same behaviour as LSExternalContext::setDoubleLowerBound()

Parameters:: lowerBound – Lower bound of the function

void LSExternalContext::setUpperBound(lsint upperBound)¶

Sets the upper bound of the external function. Only allowed if the external function is an integer function. If it is an array function, the bound will apply to all elements of the array. Only allowed in state S_Modeling. This method has the same behaviour as LSExternalContext::setIntUpperBound()

Parameters:: upperBound – Upper bound of the function.

void LSExternalContext::setUpperBound(lsdouble upperBound)¶

Sets the upper bound of the external function. Only allowed if the external function is a double function. If it is an array function, the bound will apply to all elements of the array. Only allowed in state S_Modeling. This method has the same behaviour as LSExternalContext::setDoubleLowerBound()

Parameters:: upperBound – Upper bound of the function.

void LSExternalContext::setIntLowerBound(lsint lowerBound)¶

Sets the lower bound of the external function. Only allowed if the external function is an integer function. If it is an array function, the bound will apply to all elements of the array. Only allowed in state S_Modeling.

Parameters:: lowerBound – Lower bound of the function

void LSExternalContext::setIntUpperBound(lsint upperBound)¶

Sets the upper bound of the external function. Only allowed if the external function is an integer function. If it is an array function, the bound will apply to all elements of the array. Only allowed in state S_Modeling.

Parameters:: upperBound – Upper bound of the function.

void LSExternalContext::setDoubleLowerBound(lsdouble lowerBound)¶

Sets the lower bound of the external function. Only allowed if the external function is a double function. If it is an array function, the bound will apply to all elements of the array. Only allowed in state S_Modeling.

Parameters:: lowerBound – Lower bound of the function.

void LSExternalContext::setDoubleUpperBound(lsdouble upperBound)¶

Sets the upper bound of the external function. Only allowed if the external function is a double function. If it is an array function, the bound will apply to all elements of the array. Only allowed in state S_Modeling.

Parameters:: upperBound – Upper bound of the function.

void LSExternalContext::setNanable(bool nanable)¶

Sets whether or not the function can return a NaN (Not a Number) value. Only allowed if the external function is a double function. If it is an array function, this parameter will apply to all elements of the array. Only allowed in state S_Modeling.

Parameters:: nanable – True if the function can return a NaN value, false otherwise.

LSSurrogateParameters LSExternalContext::enableSurrogateModeling()¶

Enables the surrogate modeling on the associated external function. This method changes the internal behavior of the solver: the solver now considers that the function is computationally expensive and therefore uses surrogate modeling. This method returns the LSSurrogateParameters which are used to parameterize various aspects of surrogate modeling. Note: Once the surrogate modeling is enabled, it cannot be disabled. Only allowed in state S_Modeling.

For more information, please see the section dedicated to surrogate modeling among the modeling features.

Returns:: Surrogate parameters.
Rtype:: LSSurrogateParameters