[WIP] allow deleting parameters

README.md

@@ -50,7 +50,7 @@ It is possible to change the current value of a parameter with the
 function:
 
 ```julia
-ParameterJuMP.setvalue!(p::Parameter, new_value::Number)
+fix(p::Parameter, new_value::Number)
 ```
 
 Finally, the `dual` function of JuMP is overloaded to return duals
@@ -102,7 +102,7 @@ optimize!(model)
 dual(a)
 
 # modify the value of the parameter a to 20 
-ParameterJuMP.setvalue!(a, 20)
+fix(a, 20)
 
 # solve the model with the new value of the parameter
 optimize!(model)
@@ -214,7 +214,7 @@ optimize!(model_pure)
 y_duals = dual.(y)
 
 # modify y
-ParameterJuMP.setvalue.(y, new_value_for_y)
+fix.(y, new_value_for_y)
 
 # solve problem (again)
 optimize!(model_pure)

REQUIRE

@@ -1,3 +1,4 @@
 julia 1.0
 JuMP 0.19 0.20
 MathOptInterface 0.8.4
+SparseArrays

examples/benders_quatile_regression.jl

@@ -42,12 +42,12 @@ using JuMP
 #' such as Clp, Xpress, Gurobi, CPLEX and so on)
 
 #+ echo = false
-# using GLPK
-# const OPTIMIZER = GLPK.Optimizer;
+# using Xpress
+# const OPTIMIZER = Xpress.Optimizer;
 #+
 
-using Xpress
-const OPTIMIZER = Xpress.Optimizer;
+using GLPK
+const OPTIMIZER = GLPK.Optimizer;
 
 #' TimerOutputs: a time measuring library to demonstrate the advantage of using ParameterJuMP
 using TimerOutputs
@@ -476,7 +476,7 @@ function slave_solve(PARAM, model, master_solution)
         # *parameters* can be set to new values and the optimization
         # model will be automatically updated
         β = model[2]
-        ParameterJuMP.setvalue!.(β, β0)
+        fix.(β, β0)
     else
         # JuMP also has the hability to fix variables to new values
         β_fixed = model[3]