[Coin-discuss] multiple LPs with same sparsity

[Mustafa Kilinc]

Hello,

As a subsolver to an active-set method NLP solver, I want to solve a bunch
of LPs regarding Jacobian of constraints.
Since at every iterate, the Jacobian matrix changes. But sparsity of
constraints are not different at each iterate.
Only the values in the constraints are changing but all LPs have same
sparsity pattern. What is the most efficient way to do this?

I intended to use

void modifyCoefficient<http://www.coin-or.org/Doxygen/Clp/class_clp_model.html#7319fac2234a6472005b2d45780ab9ee>(int
row, int column, double newElement, bool keepZero=false)

But from the source code, I can see that it is not implemented in
ClpMatrixBase.cpp:

void
ClpMatrixBase::modifyCoefficient(int row, int column, double newElement,
            bool keepZero)
{
  std::cerr<<"modifyCoefficient not supported - ClpMatrixBase"<<std::endl;
  abort();
}

Other than changing whole CoinPackedMatrix, is there a more efficient way?

Thanks,
Mustafa
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