getObjective method implemented.

[Vgrunert]

No description provided.

[mlubin]

This is already available through getDual(::Variable)

[Vgrunert]

Not exactly. The getDual returns the costs of one variable, whereas the redCosts returns the costs associated with the entire model.

[mlubin]

n = MathProgBase.numvar(model)
z = zeros(n)
for i in 1:n
    z[i] = getDual(Variable(model,i))
end

Accomplishes this using the existing documented methods.

[Vgrunert]

Fair enough. You decide of course. I just thought that it's a nice convenience function. But please consider the getObjective function, as it is being exported but not implemented so far.

[mlubin]

Could you describe a bit what you're trying to do and why these new methods are needed?

[Vgrunert]

Yes. The getObjective function was added simply because it was not implemented so far. I tried to use it but could not, so I added it. The getCost function is useful to get an overview of the reduced costs / shadow costs of the entire model, compared to the getDual function which provides the costs of a particular variable.

[mlubin]

Yes, exported but not implemented is a bit bizarre, not sure how that happened. @IainNZ

[Vgrunert]

Well Thanks for your consideration. I was also thinking about adding a few docstrings in the near future, so until then all the best.

[mlubin]

I think it's a good idea to provide getObjective, along with way to access constraints (#462)

[IainNZ]

Yes to getObjective, no to getCost, docstrings is good but lets hold off for now until we think about style.

[joehuchette]

I think we should merge da361e5

[mlubin]

Needs docs and tests and handling for nonlinear objectives

[Vgrunert]

Sry, I am not familiar with github. Is there anything on my part that needs to be done? I though that the request is already out and has to be accepted.

[mlubin]

You can make changes to your PR at any time by modifying the corresponding branch on your fork (in this case master). If you're up to it you could tidy the PR by removing the getCost changes and adding documentation for getObjective, otherwise we'll do it when we get a chance.