Parameter

class Parameter

Represents an AMPL parameter. The values can be float or string (in case of symbolic parameters).

Data can be assigned to the set using the methods set and setValues or using setData and an object of class DataFrame.

Parameter.isSymbolic()

Returns true if the parameter is declared as symbolic (can store both numerical and string values).

Returns:TRUE if the parameter is declared as symbolic.
Parameter.hasDefault()

Check if the parameter has a default initial value. In case of the following AMPL code:

param a;
param b default a;

the function will return TRUE for parameter b.

Returns:TRUE if the parameter has a default initial value. Please note that if the parameter has a default expression which refers to another parameter which value is not defined, this will return true.
Parameter.setValues(values)

If the argument is a list, assign the specified values to this parameter, assigning them to the parameter in the same order as the indices in the entity. The number of values in the array must be equal to the specified size.

If the argument is a data.frame, set the values of this parameter to the correponding values of the data.frame indexed over the same sets (or a subset). All columns but the last are used as index, and the last is used as value.

Parameters:values (list/data.frame) – An array of indices of the instances to be set.
Parameter.value()

Get the value of a scalar parameter.

Parameter.set(value)

Set the value of a scalar parameter.

Parameters:value – Value to be assigned.
Parameter.set(index, value)

Set the value of a single instance of this parameter.

Parameters:
  • index (list) – index of the instance to be set.
  • value – Value to be assigned.