Differences

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--- personal:blog:2017:0203_jump_for_gams_users [2023/12/22 11:20]
antonello [Definition of the "parameters"]
+++ personal:blog:2017:0203_jump_for_gams_users [2023/12/22 11:33]
antonello [Visualisation of the results]
@@ Line 132: / Line 132: @@
 Here we declare a JuML optimisation model and we give it a name. This name will be then passed as first argument to all the subsequent operations, like creation of variables, constraints and objective function.\\
-We can, if we wish, works with several models at the same time.\\
+The solver engine to use is given as argument of the ''Model()'' call.\\
-If we do not specify a solver, we let JuML use a suitable solver for the type of problem. Aside to specify the solver, we can also pass it solver-level options, e.g.:
+We could pass solver-specific options with the ''set_optimizer_attribute'' function, e.g.:
-''mymodel = Model(solver=IpoptSolver(print_level=0))''
+''set_optimizer_attribute(trmodel, "msg_lev", GLPK.GLP_MSG_ON)''
 <code julia>
 # Model declaration (transport model)
-trmodel = Model()
+trmodel = Model(GLPK.Optimizer)
 </code>
@@ Line 197: / Line 196: @@
 ==== Resolution of the model ====
-It is at this point that the solver is called and the model is passed to the solver engine for its solution. The return value is the status of the optimisation (":Optimal" if all went fine)
+It is at this point that the solver is called and the model is passed to the solver engine for its solution. The return value is the status of the optimisation (''MOI.OPTIMAL'' if all went fine)
 <code julia>
-status = solve(trmodel)
+optimize!(trmodel)
+status = termination_status(trmodel)
 </code>
@@ Line 208: / Line 208: @@
 <code julia>
-if status == :Optimal
+if status == MOI.OPTIMAL
-    println("Objective value: ", getobjectivevalue(trmodel))
+    println("Objective value: ", objective_value(trmodel))
-    println(getvalue(x))
+    println("Shipped quantities: ")
+    println(value.(x))
     println("Shadow prices of supply:")
-    [println("$p = $(getdual(supply[p]))") for p in plants]
+    [println("$p = $(dual(supply[p]))") for p in plants]
     println("Shadow prices of demand:")
-    [println("$m = $(getdual(demand[m]))") for m in markets]
+    [println("$m = $(dual(demand[m]))") for m in markets]
 else
     println("Model didn't solved")