Types of Decision Variables

jijmodeling supports integer variables IntegerVar and continuous variables ContinuousVar in addition to binary variables BinaryVar as decision variables. Unlike BinaryVar, IntegerVar and ContinuousVar require setting lower and upper bounds.

import jijmodeling as jm

# Integer variable with lower bound 0 and upper bound 10
x = jm.IntegerVar("x", lower_bound=0, upper_bound=10)
# Continuous variable with lower bound 0 and upper bound 2.5
y = jm.ContinuousVar("y", lower_bound=0.0, upper_bound=2.5)

Additionally, jijmodeling supports semi-integer and semi-continuous variables that take values within a range or 0.

# Integer variable taking values in the interval [3, 10] or 0
sx = jm.SemiIntegerVar("x", lower_bound=3, upper_bound=10)
# Continuous variable taking values in the interval [0.5, 2.0] or 0
sy = jm.SemiContinuousVar("y", lower_bound=0.5, upper_bound=2.0)

The lower and upper bounds of variables can be set to either Placeholder or numerical values.

L = jm.Placeholder("Lower")
U = jm.Placeholder("Upper")
x = jm.IntegerVar("x", lower_bound=L, upper_bound=U)
y = jm.ContinuousVar("y", lower_bound=L/2, upper_bound=U*U)