[Ipopt] re-use AmplTNLP

[Ali Baharev]

Is the following below enough? (Because it seems to work...)

(from ampl_ipopt.cpp)

retval = app->OptimizeTNLP(ampl_tnlp);

AmplTNLP* raw_ptr = static_cast<AmplTNLP*>(GetRawPtr(ampl_tnlp));

ASL_pfgh* asl = raw_ptr->AmplSolverObject();

for (int i=0; i<n_var; ++i)
  havex0[i] = 1;

// Change the initial point here

X0[0] = 0.1167;
X0[1] = 0.0370;

// etc ...

// Change bounds on the variables here

LUv[0] = 0.02;
LUv[1] = 0.20;

LUv[2] = 0.01;
LUv[3] = 0.05;

// etc ...

retval = app->ReOptimizeTNLP(ampl_tnlp);

// etc...

Any help is greatly appreciated.

Ali