[SCIP] SCIP with IPOPT with HSL

[Marco Correia]

Thank you Stefan,

When I try it, I get the following error:

calling subnlp heuristic
Exception of type: OPTION_INVALID in file "IpAlgBuilder.cpp" at line 404:
Exception message: Support for HSL_MA97 has not been compiled into Ipopt

Have you compiled IpOpt from sources? (I have installed from my package
manager as well)

Thanks!

On Thu, Oct 7, 2021 at 8:30 AM Stefan Vigerske <svigerske at gams.com> wrote:

> Hi,
>
> there is a way, depending on how the ipopt in this scip debian package
> was build.
> Try setting
>
> heuristics/subnlp/nlpoptfile = "ipopt.opt"
> heuristics/subnlp/nlpverblevel = 1
>
> and create a file ipopt.opt with content
>
> linear_solver ma27
>
>
> With the SCIP 7 that I found installed somewhere, this gives me the output
>
>   time | node  | left  |LP iter|LP it/n|mem/heur|mdpt |vars |cons |rows
> |cuts |sepa|confs|strbr|  dualbound   | primalbound  |  gap   | compl.
>    0.0s|     1 |     0 |   128 |     - |  1050k |   0 |  47 |  40 | 108
> |   0 |  0 |   0 |   0 |-1.879054e+00 |      --      |    Inf | unknown
> calling subnlp heuristic
> Exception of type: OPTION_INVALID in file
> "/nfs/optimi/usr/sw/Ipopt-3.13.2-src/Ipopt/src/Algorithm/IpAlgBuilder.cpp"
> at line 268:
>   Exception message: Selected linear solver MA27 not available.
> Tried to obtain MA27 from shared library "libhsl.so", but the following
> error occured:
> libhsl.so: cannot open shared object file: No such file or directory
> [nlpi_ipopt.cpp:1167] ERROR: Ipopt returned with application return
> status -12
>
>
> So the information that Ipopt should use MA27 is received, but it fails
> because Ipopt has been build without the HSL codes. Unless it has been
> disabled in this build of Ipopt, Ipopt then tried to load a library
> libhsl.so with the HSL codes at runtime
> (https://coin-or.github.io/Ipopt/INSTALL.html#LINEARSOLVERLOADER). So if
> you have such a library around, then you just need to make sure that it
> can be found.
>
>
> This only applies to Ipopt called by the subnlp primal heuristic. Other
> heuristics that call Ipopt do not have a "nlpoptfile" option (or I
> forgot that they have), but subnlp should be the most important one.
>
> If you work with the C API, then you can use function
> SCIPsetModifiedDefaultSettingsIpopt()
> (
> https://www.scipopt.org/doc-7.0.3/html/group__NLPIS.php#gaf626a99a6be56ab52994fe11e6ac440f)
>
> to set option "linear_solver ma27" for all calls to Ipopt.
>
>
> With the next major release, things will change and there will be a SCIP
>   option nlpi/ipopt/linear_solver to set the linear solver of Ipopt for
> all calls to Ipopt.
>
> Stefan
>
>
> On 10/6/21 18:04, Marco Correia wrote:
> > Hi,
> >
> > Is it possible to install SCIP with IPOPT with support for the HSL
> > libraries (the latter already installed) using the scip debian package,
> or
> > do I need to install SCIP from source? If so, do I also need to install
> > IPOPT from source?
> >
> > Thanks
> > Marco
> >
> >
> > _______________________________________________
> > Scip mailing list
> > Scip at zib.de
> > https://listserv.zib.de/mailman/listinfo/scip
> >
>
>
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