|
The next section of the LST file is an equation by equation then variable by variable listing of the solution returned to GAMS by the solver. Each individual equation and variable is listed by case under each block of equations and variables. The order of the equations and variables are the same as in the symbol listing described before.
---- EQU AVAILABLE RESOURCES AVAILABLE
LOWER LEVEL UPPER MARGINAL
plantcap -INF 10.000 10.000 6.000
salecontrct -INF -5.000 3.000 .
---- VAR PRODUCTION ITEMS PRODUCED BY PROCESS
LOWER LEVEL UPPER MARGINAL
makechair . . +INF -15.000
maketable . 5.000 +INF .
makelamp . . +INF -6.100
LOWER LEVEL UPPER MARGINAL
---- VAR PROFIT -INF 60.000 +INF .
PROFIT TOTALPROFIT
The columns associated with each entry have the following meaning,
| • | Equation or Variable identifier |
Notes:
| • | For variables the values in the lower and upper columns refer to the lower and upper bounds. For equations they are obtained from the (constant) right-hand-side value and from the relational type of the equation. These relationships are described in the Variables, Equations, Models and Solves chapter. |
| • | The numbers are printed with fixed precision, but the values are returned within 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. |
| 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. |
| • | This section of the listing file can be turned off by entering a line containing the statement option Solprint = off ; in the program above the solve statement. |
|