Re: [Help-glpk] GLPK 4.38 for Java under Linux
> I already thought of this way of getting rid of a variable. But > keeping all the variables in the model, even bounded to 0, won´t slow > down the simplex method? (there may be quite a lot of "removed" variables) Every time glp_simplex returns you can check status of such variables and remove those ones which became non-basic. ___ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
Re: [Help-glpk] GLPK 4.38 for Java under Linux
I already thought of this way of getting rid of a variable. But keeping all the variables in the model, even bounded to 0, won´t slow down the simplex method? (there may be quite a lot of "removed" variables) 2009/5/27 Andrew Makhorin > Rather than to "physically" remove a basic column from the problem > object with glp_del_cols you can "logically" remove it fixing it at > zero with glp_set_col_bnds(..., GLP_FX, 0, 0). In this case the basis > remains valid. > > ___ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
Re: [Help-glpk] GLPK 4.38 for Java under Linux
> Thanks for the quick and detailed answer. I will keep using the warm up > functionality, because I don?t really have an idea of which variable(s) > should enter the basis. Rather than to "physically" remove a basic column from the problem object with glp_del_cols you can "logically" remove it fixing it at zero with glp_set_col_bnds(..., GLP_FX, 0, 0). In this case the basis remains valid. ___ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
Re: [Help-glpk] GLPK 4.38 for Java under Linux
Many thanks Xypron for the way to compile the library. I will try it and get back to you if something is going wrong. Sylvain > Date: Sat, 23 May 2009 10:04:09 -0700 (PDT) > From: xypron > Subject: Re: [Help-glpk] GLPK 4.38 for Java under Linux > To: Help-glpk@gnu.org > Message-ID: <23686380.p...@talk.nabble.com> > Content-Type: text/plain; charset=us-ascii > > > Hello Sylvain, > > Sylvain Fournier wrote: > > > > I then saw that there is a glpk_4_38_java library available ( > > http://winglpk.sourceforge.net/), I tried it on Windows and it seems to > > work > > fine. But there is a problem of organization in my code, as I use a > > different Java interface when running on Linux and when running on > > Windows. > > So finally, my question on this subject is: is there a Java interface > > equivalent as the one found at http://winglpk.sourceforge.net/, but for > > Linux? In other words, has the glpk_4_38_java.dll also been compiled > under > > Linux as a .so? > > > > The commands below can be used to create the libraries. > Currently I am puzzled because the call to GLPK.glp_create_prob() works > fine, while > GLPK.glp_mpl_alloc_wksp() fails with > java: symbol lookup error: /usr/local/lib/libglpk_4_38_java.so: undefined > symbol: glp_mpl_alloc_wksp > > Best regards > > Xypron > > > # download and unzip > wget ftp://ftp.gnu.org/gnu/glpk/glpk-4.38.tar.gz > tar -xzf glpk-4.38.tar.gz > wget > > http://freefr.dl.sourceforge.net/sourceforge/winglpk/glpsol_dll-4.38-32bit.zip > unzip -o glpsol_dll-4.38-32bit.zip > > # make and install glpk > cd glpk-4.38 > ./configure --enable-dl --enable-odbc > sudo make install > > # create libraries with swig > cd swig > mkdir src > mkdir src/java > mkdir java > mkdir java/org > mkdir java/org/gnu > mkdir java/org/gnu/glpk > swig -c++ -java -package org.gnu.glpk -o src/java/glpk_wrap.c -outdir > java/org/gnu/glpk glpk.i > g++ -c -fpic src/java/glpk_wrap.c -I../include > -I/usr/lib/jvm/java-6-sun/include -I/usr/lib/jvm/java-6-sun/include/linux > g++ -shared glpk_wrap.o -lglpk -lltdl -lgmp -o libglpk_4_38_java.so > sudo cp libglpk_4_38_java.so /usr/local/lib > cd java/org/gnu/glpk > javac *.java > cd ../../.. > jar cf glpk.jar * > > # make and try example > cd ../../examples > javac -cp ../swig/java/glpk.jar GLPKSwig.java > java --cp ../swig/java/glpk.jar:. GLPKSwig > ___ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
Re: [Help-glpk] GLPK 4.38 for Java under Linux
2009/5/23 Andrew Makhorin > > > Lpx_warm_up will be replaced by glp_warm_up, which will provide the > same functionality. > > Thanks for the quick and detailed answer. I will keep using the warm up functionality, because I don´t really have an idea of which variable(s) should enter the basis. Sylvain ___ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
Re: [Help-glpk] GLPK 4.38 for Java under Linux
Hello Andrew, the error was caused by some old library installed in /usr/lib while the default installation path of GLPK is /usr/local/lib. Best regards Xypron Andrew Makhorin wrote: > >> Currently I am puzzled because the call to GLPK.glp_create_prob() works >> fine, while >> GLPK.glp_mpl_alloc_wksp() fails with >> java: symbol lookup error: /usr/local/lib/libglpk_4_38_java.so: undefined >> symbol: glp_mpl_alloc_wksp > > It is unclear. Libtool must export all symbols prefixed with 'glp_': > > libglpk_la_LDFLAGS = -version-info @VERINFO@ \ > -export-symbols-regex '^(glp_|_glp_lpx_).*' > > Looks like there is something wrong in libtool, or not? > > > > ___ > Help-glpk mailing list > Help-glpk@gnu.org > http://lists.gnu.org/mailman/listinfo/help-glpk > > -- View this message in context: http://www.nabble.com/GLPK-4.38-for-Java-under-Linux-tp23671681p23687832.html Sent from the Gnu - GLPK - Help mailing list archive at Nabble.com. ___ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
Re: [Help-glpk] GLPK 4.38 for Java under Linux
> Currently I am puzzled because the call to GLPK.glp_create_prob() works > fine, while > GLPK.glp_mpl_alloc_wksp() fails with > java: symbol lookup error: /usr/local/lib/libglpk_4_38_java.so: undefined > symbol: glp_mpl_alloc_wksp It is unclear. Libtool must export all symbols prefixed with 'glp_': libglpk_la_LDFLAGS = -version-info @VERINFO@ \ -export-symbols-regex '^(glp_|_glp_lpx_).*' Looks like there is something wrong in libtool, or not? ___ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
Re: [Help-glpk] GLPK 4.38 for Java under Linux
> I have another question about my algorithm. I am using a Branch Price > scheme. When I add variables, I want to use the basis of the previous run > as the first basis of the current run (I don´t want to solve the model > from scratch each time!) If you add new column(s), glp_add_cols makes them non-basic, so the current basis as well as the basis factorization remain valid. Note that by default the glpk simplex solver (glp_simplex) starts the search from the current basis defined in the problem object, so if the basis is valid, you do not need to call lpx_warm_up. > When I delete columns however, it may occur that > one of them was in the basis, that consequently is not valid any more. > Is there a simple way for me to use the same basis in the next run in > case it was not modified, and update this basis in the case it has lost > at least one variable? You can use the routine glp_get_col_stat to determine whether a column is basic or non-basic. If the column is basic, deleting it invalidates the basis. So if you want the simplex solver to continue the search, you should use the routine glp_set_row_stat/glp_set_col_stat to change the status of some appropriate non-basic row/column to GLP_BS, i.e. to make the basis valid. > (I used the warm_up function and I was looking at > its return code, but this function seems to be deprecated on the newest > versions.) Lpx_warm_up will be replaced by glp_warm_up, which will provide the same functionality. ___ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
Re: [Help-glpk] GLPK 4.38 for Java under Linux
Hello Sylvain, Sylvain Fournier wrote: > > I then saw that there is a glpk_4_38_java library available ( > http://winglpk.sourceforge.net/), I tried it on Windows and it seems to > work > fine. But there is a problem of organization in my code, as I use a > different Java interface when running on Linux and when running on > Windows. > So finally, my question on this subject is: is there a Java interface > equivalent as the one found at http://winglpk.sourceforge.net/, but for > Linux? In other words, has the glpk_4_38_java.dll also been compiled under > Linux as a .so? > The commands below can be used to create the libraries. Currently I am puzzled because the call to GLPK.glp_create_prob() works fine, while GLPK.glp_mpl_alloc_wksp() fails with java: symbol lookup error: /usr/local/lib/libglpk_4_38_java.so: undefined symbol: glp_mpl_alloc_wksp Best regards Xypron # download and unzip wget ftp://ftp.gnu.org/gnu/glpk/glpk-4.38.tar.gz tar -xzf glpk-4.38.tar.gz wget http://freefr.dl.sourceforge.net/sourceforge/winglpk/glpsol_dll-4.38-32bit.zip unzip -o glpsol_dll-4.38-32bit.zip # make and install glpk cd glpk-4.38 ./configure --enable-dl --enable-odbc sudo make install # create libraries with swig cd swig mkdir src mkdir src/java mkdir java mkdir java/org mkdir java/org/gnu mkdir java/org/gnu/glpk swig -c++ -java -package org.gnu.glpk -o src/java/glpk_wrap.c -outdir java/org/gnu/glpk glpk.i g++ -c -fpic src/java/glpk_wrap.c -I../include -I/usr/lib/jvm/java-6-sun/include -I/usr/lib/jvm/java-6-sun/include/linux g++ -shared glpk_wrap.o -lglpk -lltdl -lgmp -o libglpk_4_38_java.so sudo cp libglpk_4_38_java.so /usr/local/lib cd java/org/gnu/glpk javac *.java cd ../../.. jar cf glpk.jar * # make and try example cd ../../examples javac -cp ../swig/java/glpk.jar GLPKSwig.java java --cp ../swig/java/glpk.jar:. GLPKSwig -- View this message in context: http://www.nabble.com/GLPK-4.38-for-Java-under-Linux-tp23671681p23686380.html Sent from the Gnu - GLPK - Help mailing list archive at Nabble.com. ___ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
