Originally posted by: BerkUstun

I am wondering if anyone knows how to remove display output from the CPLEX MATLAB API. I am currently using the CPLEX 12.2 API with the 64 bit version of MATLAB 2011a on Unix. I will illustrate an issue with the following example:

Say I create an LP object in MATLAB using:

LP = Cplex()
% Set LP.Model.A, LP.Model.lhs,LP.Model.rhs, LP.Model.ub, LP.Model.lb

When I try to solve this object with the solve method, CPLEX usually generates some output. That is:

>> LP.solve
 
Using devex.
Using devex.
 
Primal simplex solved model.
 
ans = 
 
          status: 1
    statusstring: 'optimal'
            time: 0.0217
          objval: -60
               x: [4x1 double]
          method: 1
            dual: [3x1 double]
              ax: [3x1 double]
     reducedcost: [4x1 double]
           basis: [1x1 struct]

In the past, I could remove all of this output by replacing the Display Function with an empty matrix. That is

LP.DispFunction = []

Unfortunately, doing this now this only removes part of the output. When I now solve the LP, I still obtain:

Using devex.
Using devex.
 
Primal simplex solved model.

Does anyone know how to remove the remaining output? As a side note, using a semi-colon to suppress output does not resolve the issue (i.e. using "LP.solve;" instead of "LP.solve").
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: John Cui

Actually, you should use:

LP.DisplayFunc = []

to disable the output.

John Cui
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: BerkUstun

Sorry that was just a typo. I will correct it. The issue still stands with LP.DisplayFunc = [].
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#DecisionOptimization

Originally posted by: BerkUstun

Also, I noticed that I do not get any additional output when I force CPLEX to solve the LP using Simplex.

LP.Param.lpmethod.Cur = 1;

My guess is that the following output:

Using devex.
Using devex.
Primal simplex solved model.

is created by the 'automatic' LP algorithm selection feature in CPLEX (i.e. when LP.Param.lpmethod.Cur = 0).

Is there any setting to have it still select the LP algorithm automatically but not display this output?
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: John Cui

1. In my MATLAB 2008b + windows xp + cplex12.2, DisplayFunc works fine, let me check in MATLAB2011a.
2. You can set simplex display to 2 by LP.Param.simplex.display.Cur = 2 to display more simplex log, then you will know which lpmethod you are using.
And also, you can use LP.getChgParam method to get changed parameters.

John Cui
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: John Cui

I tried MATLAB2011a, DisplayFunc works fine:

LP = Cplex();
LP.DisplayFunc = [];
LP.solve()
ans = 
 
          status: 1
    statusstring: 'optimal'
            time: 0.0160
          objval: 0
          method: 2
 
 
LP = Cplex();
LP.solve()
Parallel mode: deterministic, using up to 2 threads for concurrent optimization.
Tried aggregator 1 time.
No LP presolve or aggregator reductions.
 
Dual simplex solved model.
 
 
ans = 
 
          status: 1
    statusstring: 'optimal'
            time: 0.0310
          objval: 0
          method: 2

John Cui
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

These settings should allow CPLEX to select the LP algorithm automatically, but not display any output:

LP.DisplayFunc = [];
LP.Param.simplex.display.Cur = 0;
LP.Param.barrier.display.Cur = 0;

#CPLEXOptimizers
#DecisionOptimization

Originally posted by: John Cui

Actually,

LP.DisplayFunc = [];

is enough.

John Cui
#CPLEXOptimizers
#DecisionOptimization