Quick start - Gams

have full machine accuracy.
The single dots '.' represent zeros.
If present EPS is the GAMS extended value that means very close to but different from
zero.
It is common to see a marginal value given as EPS, since GAMS uses the convention that
marginals are zero for basic variables, and nonzero for others.
EPS is used with non-basic variables whose marginal values are very close to, or actually,
zero, or in nonlinear problems with superbasic variables whose marginals are zero or very
close to it.
For models that are not solved to optimality, some items may additionally be marked
with the following flags.
Flag Description
Infes The item is infeasible. This mark is made for any entry whose level
value is not between the upper and lower bounds.
Nopt The item is non-optimal. This mark is made for any non-basic
entries for which the marginal sign is incorrect, or superbasic ones
for which the marginal value is too large.
Unbnd The row or column that appears to cause the problem to be
unbounded.
The marginal output generally does not have much meaning in an MCP or CNS model.
Variable solution report
The next section of the LST file is a variable by variable listing of the solution returned to
GAMS by the solver. Each individual variable case is listed. For our three examples the reports
are as follows
LOWER LEVEL UPPER MARGINAL
---- VAR Z -INF 9950.000 +INF .
---- VAR Xcorn . 50.000 +INF .
---- VAR Xwheat . 50.000 +INF .
---- VAR Xcotton . . +INF -13.000
LOWER LEVEL UPPER MARGINAL
---- VAR P . 3.000 +INF .
---- VAR Qd . 10.000 +INF .
---- VAR Qs . 10.000 +INF .
LOWER LEVEL UPPER MARGINAL
---- VAR ba -INF 1.000 +INF .
---- VAR so4 -INF 1.000 +INF .
---- VAR baoh -INF 4.802 +INF .
---- VAR oh -INF 1.000 +INF .
---- VAR hso4 -INF 0.980 +INF .
---- VAR h -INF 1.000 +INF .
Courtesy of B.A. McCarl, October 2002 22