> I would like to ask that from the result output > of the model file for example shown below i > would like to get information that what exactly is > what > 1. What does "St" stand for n what are "B" "NL" > denoted. > 2. What does it mean when the marginal value is "positive" and > "esp" and what if its "Negative value" > Problem: tspmatrixfin > Rows: 71 > Columns: 191 > Non-zeros: 850 > Status: OPTIMAL > Objective: path = 4002.331 (MINimum) > > No. Row name St Activity Lower bound Upper bound Marginal > ------ ------------ -- ------------- ------------- ------------- > ------------- > 1 path B 4002.33 > 2 Travelled_distance[0] > NL 2 2 > 263.609 > 3 Travelled_distance[1] > NL 2 3 > esp > 4 Travelled_distance[2] > NL 2 2 > -83.12
For rows: St = B means the corresponding constraint is inactive, i.e. its auxiliary variable is basic. St = NL means the corresponding constraint is active, i.e. its auxiliary variable is non-basic (on the lower bound). If marginal value is d > 0, the corresponding constraint is active and increasing its lower bound by one will lead to increasing the objective function by +d (until the basis will have been changed). Analogously, if d < 0, the corresponding constraint is active and decreasing its upper bound by one will lead to increasing the objective by -d. If marginal value is printed as eps, this means that its value is close to zero, i.e. the corresponding solution is degenerative. P.S. I recommend you to consult any textbook on linear programming. Andrew Makhorin _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
