Quick start - Gams

GAMS is fundamentally built to allow exploitation of algebraic features like summation
notation. Specifically suppose xi is defined with three elements
Algebra
∑
i
x
This can be expressed in GAMS as
where
z = SUM(I, X(I));
i
=
x
1
+
x
I is a set in GAMS
z is a scalar or variable
X(I) is a parameter or variable defined over set I
and the sum automatically treats all cases of I.
Such an expression can be included either in a either a model equation .. specification or in an
item to be calculated in the code. Let me now remake the first 2 examples better exploiting the
GAMS algebraic features
2
+
Revised algebra exploiting optimization example
Courtesy of B.A. McCarl, October 2002 24
x
3