<div dir="ltr">Hi Everyone,<div><br></div><div>I am researching a different way to construct the Hessian in a control setting.<br><div><br></div><div>Is there a way to know the direction of descent during a given calculation step in Ipopt? In particular is there a way, from a user's point of view, to access the calculated values of <b>d_k^x, d_k^\lambda</b> and <b>d_k^z</b> as well as the step sizes <b>\alpha_k</b> and <b>\alpha_k^z </b>from the Ipopt paper below? Are they available from the root TNLP class?</div><div><br></div><div>I see from the header that there is a method that I suspect may contain these quantities. Are there example of usage anywhere?</div><div>  virtual bool intermediate_callback(AlgorithmMode mode,<br>                    Index iter, Number obj_value,<br>                    Number inf_pr, Number inf_du,<br>                    Number mu, Number d_norm,<br>                    Number regularization_size,<br>                    Number alpha_du, Number alpha_pr,<br>                    Index ls_trials,<br>                    const IpoptData* ip_data,<br>                    IpoptCalculatedQuantities* ip_cq)</div><div><br></div><br><div><a href="http://cepac.cheme.cmu.edu/pasilectures/biegler/ipopt.pdf" target="_blank">http://cepac.cheme.cmu.edu/pasilectures/biegler/ipopt.pdf</a> <br clear="all"><div><br></div><div>Thank you,<br></div>-- <br><div dir="ltr" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr">Panos Lambrianides</div><div dir="ltr"><div><a href="mailto:panos@soe.ucsc.edu" target="_blank">panos@soe.ucsc.edu</a></div><div><br></div><div><br></div><div><br></div><div><br></div></div></div></div></div></div></div></div></div></div>