[Ipopt] Iterations number changed after using sparse matrix ma27, reasonable?

[lqc234]

Hi everyone, hi Andreas!
I use Ipopt 3.6.1 in my application and it works well.At the first,it iterates 12 times and optimal  solution found. However I want to use sparse matrix technology which ma27 supports in jacobi and hessian to improve my application. The optimal solution also be founded,but the iteration number changed to 19. Is this situation reasonable? I have thought the results is the same whether or not using the sparse matrix technique. Appreciate for any suggestion!
 
  Thank you in advance!

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