ILOG CPLEX C++ API 9.0 Reference Manual

IloCplex::VariableSelect
coordinate but differ in the value of f(x). Such a difference is known as a step in the
piecewise linear function, and such a function is known as discontinuous.
Syntactically, a step is represented in this way:
◆ The value of the first point of a step in the array of slopes is the height of the step.
◆ The value of the second point of the step in the array of slopes is the slope of the
function after the step.
By convention, a breakpoint belongs to the segment that starts at that breakpoint.
In Concert Technology, a discontinuous piecewise linear function is represented as an
instance of the class IloPiecewiseLinear (the same class as used for continuous
piecewise linear functions).
For examples of discontinuous piecewise linear functions, see this topic in the ILOG
CPLEX User's Manual.
Using IloPiecewiseLinear
Whether it represents a continuous or a discontinuous piecewise linear function, an
instance of IloPiecewiseLinear behaves like a floating-point expression. That
is, you may use it in a term of a linear expression or in a constraint added to a model
(an instance of IloModel).
ILOG CPLEX C++ API 9.0 REFERENCE M ANUAL 229