documents/tutorial/eplex.tex

296 In this case, there is an optimal solution of 710.0:
305 instantiated by the solver. However, the `solution' values, i.e.\ the
309 solution value for the variable (e.g., \verb'A2' has the solution value of
315 One reason the problem variables are not assigned their solution values is
320 \subsection{Getting more solution information from the solver}
322 The solution values of the problem variables can be obtained by
324 previous section can be modified to return the solution values:
332             % f. set the problem variables to their solution values
338 In line \verb'f', \verb'eplex_var_get/3' is used to obtain the solution
340  specifies that we want the solution value for the variable to be returned.
341 Here, we instantiate the problem variable itself to the solution value
419 problem. However, the solution values are not integral:
443 the external solver will only assign integer solution values to the
464 returns the solution values taking into account if the variables have been
469   will only assign intergral solution values to them), but does
543 In general, this initial LP solution contains non-integer assignments
564       mip: eplex_var_get(X, solution, XVal),
579 Eventually, if the problem has a solution, all the integer
580 variables will be `labelled' with integer values, resulting in a solution to the
582 needs to backtrack into the tree to search for a better solution by trying
584 existing solution value as a bound.
608 fractional solution value for a variable. The criterion we want to use is
609 to invoke the solver only if this old solution value is excluded by the new
614 implements a MIP solution for the
648         %    invoked when any solution value is outside the variable bounds
654                  (foreach(V, Vars) do mip: eplex_var_get(V,solution,V))
658         % Find a variable X which does not have an integer solution value
669             % cannot find any integer violations; found a solution
673 % returns Var with solution value Val which violates the integer constraint
675         mip: eplex_var_get(X, solution, RelaxedSol),
689 \verb'eplex_solve/1' for an initial solution
714 branch with the integer range closer to the relaxed solution value.
716 \verb'X $=< 4' is tried first since the solution value of 4.2 is
723 each labelling of the variables. We also get the solution values for the
725 The final value returned in \verb'Cost' (and {\tt Vars} for the solution
799     \item round the solution for T1 to the nearest integer and instantiate it
802     \item round the solution for T2 to the nearest integer and instantiate it