<font face="Default Sans Serif,Verdana,Arial,Helvetica,sans-serif" size="2">Dear Ipopt developer/users,<br><br>I would like to know if there is a way to make sure that IPOPT operates only within the feasible region (through AMPL options). I am encountering a situation where defined variables are explicitly constrained, something along the lines of<br><br>var y >= 0;<br>var d = "some stuff"<br>subject to dpos: d >= 0;<br>var xi = y / d;<br>subject to xipos: xi >= 0;<br></font><font face="Default Sans Serif,Verdana,Arial,Helvetica,sans-serif" size="2">var w = exp(-xi);<br></font><br><font face="Default Sans Serif,Verdana,Arial,Helvetica,sans-serif" size="2">however, IPOPT aborts abnormally out with a message<br><br>Error evaluating "var =" definition 697: <br>can't evaluate exp(3632.5): No such file or directory.<br><br>because (I guess) it cannot evaluate things like<br>var w = exp(-xi);<br>elsewhere in the model.<br><br>I am sure that the initial point supplied to the solver is feasible. Any suggestions would be greatly appreciated (I have already tried to replace defined variables with constraints -- that causes other problems).<br><br>Thanks. Best,<br>Mikhail<br><br></font>