<p dir="ltr">Hi Brad!</p>
<p dir="ltr">You probabably need to set the "fixed_variable_treatment" option to get the correct multipliers:</p>
<p dir="ltr"><a href="http://www.coin-or.org/Ipopt/documentation/node43.html#SECTION000114060000000000000">http://www.coin-or.org/Ipopt/documentation/node43.html#SECTION000114060000000000000</a></p>
<p dir="ltr">Best regards,<br>
Joel</p>
<div class="gmail_quote">On Jul 20, 2015 12:03 AM, "Brad Bell" <<a href="mailto:bradbell@seanet.com">bradbell@seanet.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Consider the case where the lower limit and upper limit is equal for one of the primal variable components; e.g.,<br>
x_l[j] = x_u[j]<br>
in the get_bounds_info function.<br>
<br>
I appears that in this case, finalize_solution will have<br>
z_L[j] = z_U[j] = 0.<br>
Is this how Ipopt works ?<br>
<br>
If so, consider the optimization problem<br>
minimize x[0]^2 subject to 1 <= x[0] <= 1<br>
In this case, it appears to me, that the final multiplier z_L[0], in finalize_solution, should be non-zero.<br>
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