[Ipopt] Ipopt Digest, Vol 96, Issue 18

[Rafael de Pelegrini Soares]

Dear Alberto,

A "NoClassDefFoundError" meas that the class org.coinor.Ipopt is not on the
path of your project. You are forgetting to add the jar file or the class
files on the path of your project. If you are using Eclipse this should be
reported during the compilation step and not only at run-time.

Regards.


On Fri, Jan 11, 2013 at 1:39 PM, Alberto Calzada <albertocalsa at gmail.com>wrote:

> Hello Edson,
>
> First of all, thank you very much for your prompt reply. I am sorry for
> the delay in answering you, but I have been trying several possible
> solutions and I still have the same problem.
>
> As you adviced me, I tried to use the alternative constructor, but I
> always keep getting the same NoClassDefFoundError in org/coinor/Ipopt. I
> don't really know how to approach this problem now, so any possible
> solution would be more than welcome.
>
> Many thanks,
>
> Alberto
>
>
> On 30 December 2012 14:26, Edson Cordeiro do Valle <edsoncv at enq.ufrgs.br>wrote:
>
>>    Hello Alberto
>>
>> If you run HS71 without any issue, that can be a problem of your search
>> path.
>> Notice the "alternative" ipopt constructor (Ipopt.java):
>>         public Ipopt(String path, String DLL){
>>             // Loads the library
>>             File file = new File(path, System.mapLibraryName(DLL));
>>             System.load(file.**getAbsolutePath());
>>         }
>> and
>>     public static final String DLLNAME = "jipopt";
>>     /** The relative path where the native DLL is found */
>>     public static final String DLLPATH = "lib";
>> so, you need to use this second constructor and send the jipopt.dll path
>> appropriatelly. Or create a "lib" folder in your project and place the .dll
>> there. This is probably the source of your problem.
>>
>> Your second problem (get the final values) you can get it with the
>> "getState()" method.
>>
>> Regards
>> Edson
>>
>>
>>
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>>> Today's Topics:
>>>
>>>     1. Some issues about JIpopt usage (Alberto Calzada)
>>>
>>>
>>> ------------------------------**------------------------------**
>>> ----------
>>>
>>> Message: 1
>>> Date: Fri, 28 Dec 2012 15:20:33 +0000
>>> From: Alberto Calzada <albertocalsa at gmail.com>
>>> To: Ipopt at list.coin-or.org
>>> Subject: [Ipopt] Some issues about JIpopt usage
>>> Message-ID:
>>>         <CAOtPDdA-**X2fazQ8vqvGSnkPBeWw43RByavejps**
>>> oCjtu6AedEyg at mail.gmail.com<CAOtPDdA-X2fazQ8vqvGSnkPBeWw43RByavejpsoCjtu6AedEyg at mail.gmail.com>
>>> >
>>> Content-Type: text/plain; charset="iso-8859-1"
>>>
>>> Dear List,
>>>
>>> First of all, many thanks for providing this great tool to solve
>>> non-linear
>>> constrained optimisation problems in Java. I have found the use of this
>>> interface easy and even enjoyable! Good job!
>>>
>>> However, I have found a couple of issues...
>>>
>>> The first one: I am working in a big project Eclipse and I really don't
>>> know why (even if I execute the hs071.java class without any issue at
>>> all)
>>> I can't execute my class, which has been already implemented!
>>> I keep on having the runtime error "java.lang.**NoClassDefFoundError:
>>> org/coinor/Ipopt". I have checked it and both the DLL file (for Win32)
>>> and
>>> also the JIpopt JAR are included in the JAR of my project so I don't know
>>> what can I do! I have cleaned my project, restated Eclipse and I always
>>> get
>>> this error... Any ideas?
>>> I am working on a Windows7 64-bits computer. Could that be the problem?
>>>
>>> My second issue is regarding how can I get the optimal solution for my
>>> problem variables retrieved by JIpopt. I need to assign those values to
>>> my
>>> decision making scheme, but I haven't found any method in the Ipopt class
>>> or in the hs071 example.
>>>
>>> I hope to hear from you soon,
>>> Many thanks,
>>> Best regards,
>>>
>>> Albe
>>>
>>>
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>>
>
>
>
> --
> *--
> *
>
> *Mr Alberto Calzada
> Full-time PhD Candidate*
>
> *Room 16J25 *
>
> *School of Computing and Mathematics
> Faculty of Computing and Engineering*
>
> *University of Ulster at Jordanstown Campus
> Northern Ireland, UK
> Email: Calzada-A at email.ulster.ac.uk*
>
> *Tel:  +44 28 90361114 *
>
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>
>


-- 
Prof. Rafael de Pelegrini Soares, D.Sc
Chemical Engineering Department - UFRGS
rafael at enq.ufrgs.br, rafael.enq at gmail.com
office: +55 51 3308 3528
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