<DIV>hi dear Zhang </DIV> <DIV> </DIV> <DIV>you can simply convert [an inequality constraint] to [an equality constraint and a simple bound] as shown in this example:</DIV> <DIV> </DIV> <DIV>inequality constraint: x1^3 + 4 >= 5*x2</DIV> <DIV> </DIV> <DIV>move all expressions into left side we have:</DIV> <DIV>(x1^3 + 4 - 5*x2) >= 0</DIV> <DIV> </DIV> <DIV>it is equal to:</DIV> <DIV> <DIV>(x1^3 + 4 - 5*x2) + S = 0 , AND, S <= 0</DIV> <DIV> </DIV> <DIV>this is true because if f(x) should be GREATER than zero, then f(x) plus "a negative value" will be EQUAL to zero.</DIV> <DIV> </DIV> <DIV>so you should define a new variable (S) and specify its upper bound to zero (S<=0) and use equality constraint (x1^3 +
4 - 5*x2) + S = 0 instead of original inequality constraint.</DIV> <DIV> </DIV> <DIV>i hope this help you</DIV> <DIV>if you do not understand this, i can send an example file for you..</DIV> <DIV> </DIV> <DIV> </DIV> <DIV>good luck</DIV> <DIV>saeed serpooshan</DIV></DIV> <DIV> </DIV> <DIV> </DIV> <DIV> </DIV> <DIV>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>></DIV> <DIV><BR><BR><B><I>zwerhu <zwerhu@graduate.shu.edu.cn></I></B> wrote:</DIV> <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">Dear Dr. Andreas,<BR> I have a problem to ask you for some help.My major is not about optimization, but I must solve some NLP problems for the current research
aim. Though I am not very good at nonlinear programming theory, I managed to use Ipopt to solve some NLP problems which has only equality constraints. But I have really some difficulties in solving the problems with inequality constraints. I have studied your theses about Ipopt and you said that we can use the slack variables. But I can't find the example that treat about this kind of problems in your paper and there're no examples in the Matlab interface files that I downloaded. Can you give me a simple example that solve the NLP with inequality constraint(including some details) ? Or can you show me the paper of yours that concern about this kind of problem? I think that there should be some examples about this kind of problems in the example files of Ipopt Matlab interface. I know this may cost you some time, and we will be very thankful to your
help. <BR><BR><BR> Best Wishes<BR> W. Zhang </BLOCKQUOTE><p>
<hr size=1>Yahoo! Shopping<br>
Find Great Deals on Holiday Gifts at <a href="http://us.rd.yahoo.com/mail_us/footer/shopping/*http://shopping.yahoo.com/;_ylc=X3oDMTE2bzVzaHJtBF9TAzk1OTQ5NjM2BHNlYwNtYWlsdGFnBHNsawNob2xpZGF5LTA1
">Yahoo! Shopping</a>