[Clp] problems with time-out when using primal Simplex

[Kish Shen]

Hi,

I have been doing some timings with Cbc/Clp (trunk branch, downloaded 
via svn on 4 Nov), and it seems that when Primal Simplex is used to 
solve a linear problem, the time-out setting is ignored.

I use OsiClpSolverInterface to access the Clp solver, and set the method 
  to Primal Simplex via

Solver->setHintParam(OsiDoDualInInitial, doDual, OsiHintDo, NULL)

where doDual is set to false for Primal Simplex, Solver is a 
OsiClpSolverInterface *.

To set the timeout, I use ClpModel's setMaximumSeconds():

Solver->getModelPtr()->setMaximumSeconds(time)

this is done after the setHintParam to select Primal method above.

This timeout seems to work if I am using Dual Simplex (and also for 
ClpInterior), but not with Primal. The solver seems to run until the 
problem is solved. I initially set the timeout to 300 seconds, and I was 
getting problems that took over 1000 seconds to solve returning the 
optimal solution. I then set the time-out to 2 seconds, and problems 
that took 58 seconds also did not time-out.

I looked at the HTML (generated by DOxygen, I think?) documentation for 
setMaximumSeconds, and there seem to be some error, because the text for 
the method says `Number of rows', which does not seem to describe the 
method. This 'Number of rows' occurs for other methods, such as 
setMaximumIterations(), getIterationCount() -- perhaps it is some 
`default' string when there is no description? Should it be `No 
description' instead?

Thanks and cheers,

Kish

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