Suppressing output for "default" solver

[vgupta1]

Hey all,

Is there a way to instruct the solver object to suppress logging information in a solver-agnostic way? For example, I can always write:

m = Model(solver=GurobiSolver(OutputFlag=0) )

but this assumes the user's machine has Gurobi installed. If I write:

m = Model()

and let's JuMP sort it out on the backend, depending on the choice of solver, it dumps a ton of auxiliary stuff to the console. (This is particularly annoying if you're calling JuMP within the context of another program, or writing tests.)

Is there an existing solver-independent way of suppressing output? Ideally, I"d like to write something like:

m = Model(quiet=true)

and have JuMP both select the solver, and set the default option to suppress output. Thoughts?

Vishal

[mlubin]

Related to #91. We currently don't have a way to set options in a solver-agnostic way. In this particular case you don't need to set any solver options, just redirect STDOUT before solving:

TT = STDOUT # save original STDOUT stream
redirect_stdout()
solve(m)
redirect_stdout(TT) # restore STDOUT

Not sure if we should implement this trick in JuMP or leave it for users.

[joehuchette]

Ideally we would expose solver-independent parameters like this (e.g. Model(quiet=true)), while making the interface clearly distinct from the usual way of passing solver parameters. Not sure how to do that, though.

[vgupta1]

Thanks Miles! I'll use that for now, although fwiw, it seems a little
cludgey to me. I agree with Iain in #91 that there should be a sort of
generic way to set generic options...

On Sat Nov 29 2014 at 9:05:15 PM Joey Huchette notifications@github.com
wrote:

Ideally we would expose solver-independent parameters like this (e.g.
Model(quiet=true)), while making the interface clearly distinct from the
usual way of passing solver parameters. Not sure how to do that, though.

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Reply to this email directly or view it on GitHub
#325 (comment).

[mlubin]

Added this to the FAQ. Closing in favor of #91.