<HTML><HEAD></HEAD>
<BODY dir=ltr>
<DIV dir=ltr>
<DIV style="FONT-FAMILY: 'Calibri'; COLOR: #000000; FONT-SIZE: 12pt">
<DIV>I’ve observed that constraining the objective function to be <= a number
can cause Ipopt to look further and find a better solution, in some
instances.</DIV>
<DIV>The following results were done in my Mathematica interface to Ipopt.</DIV>
<DIV> </DIV>
<DIV>Constraining the objective function to be <= –2 improved the solution
from – 0.71 to – 2.39. Of course, in some cases,</DIV>
<DIV>I get an infeasible problem.</DIV>
<DIV> </DIV>
<DIV>expr = Exp[Sin[50*x]] + Sin[60*Exp[y]] + Sin[70*Sin[x]] + Sin[Sin[80*y]] -
Sin[10*(x+y)] + (x^2+y^2)/4;</DIV>
<DIV> </DIV>
<DIV>callIpOpt[ expr, {} , {{x, –1 ,0, 1}, {y, -1, 0, 1}}] [[{1,2,-1}]]</DIV>
<DIV>{-0.713075, {x –> -0.0223022, y –> -0.00472762},
Solve_Succeeded}</DIV>
<DIV> </DIV>
<DIV>callIpOpt[ obj, {obj == expr, obj <= -2}, {{obj, -5, –2 ,0}, {x,
-1, 0, 1}, {y, -1, 0, 1 }}] [[{1,2,-1}]]</DIV>
<DIV>{-2.38833, {obj- > -2.38833, x –> 0.344918, y –> -0.887746},
Solve_Succeeded}</DIV>
<DIV> </DIV>
<DIV>Are there any option settings which could enhance this property?</DIV>
<DIV> </DIV>
<DIV>Thanks</DIV>
<DIV> </DIV>
<DIV>Frank Kampas</DIV>
<DIV> </DIV>
<DIV> </DIV></DIV></DIV></BODY></HTML>