From help-octave-request at bevo dot che dot wisc dot edu Wed Feb 20 09:12:07 2002
Subject: Re: Linking C++ classes in non-octave applications [liboctave]
From: "Jan D'hooge" <jan dot dhooge at uz dot kuleuven dot ac dot be>
To: Douglas Eck <doug at idsia dot ch>
CC: help-octave at bevo dot che dot wisc dot edu
Date: Wed, 20 Feb 2002 16:06:48 +0100

Thanks for the tip... After upgrading some of the libraries on my
Mandrake (8.0) system, I managed to compile the attached stand-alone C++
program as well. However, I had to link to the lapack library (-llapack)
as well.


Thanks again,

Jan.


Douglas Eck wrote:
> 
> Hi Jan,
> 
> This is not so hard to do. The challenge is in making sure you link
> to the appropriate libs when you compile your application. As of
> octave-2.1.35 you need to link to quite a few libs. However, John Eaton
> said in a posting some time back that this will be simplified
> quite a bit in 2.1.36. Once you can compile a simple liboctave app,
> you are free to link to other libraries. I for example have linked
> a liboctave-linked app to some MIDI libs that are themselves linked dynamically
> against libqt. And everything worked out.
> 
> Let me say that it's a quite nice environment to work in. You have access to
> all of the octave data structures. Also, you have the ability to call your program
> from the octave interpreter, making it easy to pass in and write out
> data to disk via .mat files. And with a standalone app you can use
> easily use gdb and gprof!
> 
> I included a Makefile and helloWorld.cc which compiles on
> my debian box. Your mileage may vary depending on how octave
> was compiled. Also, if you're using windows, then please
> let me know if you have success. I haven't been able to get
> a standalone app to compile on windows (cygwin).
> 
> Finally, a special note on kpathsea. As of now, octave uses a modified kpathsea.
> This means that you must have the libkpathsea from the octave sources!
> You'll see in my Makefile that I add /usr/src/octave-2.1.35/kpathsea
> to the library path. Hopefully upstream changes will be made to kpathsea
> so that this is no longer necessary... but I'm not clear on the status
> of this right now.
> 
> Cheers,
> Doug
> 
> Jan D'hooge wrote:
> 
> > Hi,
> >
> > I'm new to the octave source code but I thought of using (part of) it as
> > a basic vector/matrix/arrays C++ library. I compiled the Octave
> > libraries without too much problem but linking them with my own
> > applications doesn't seem soo straight forward.
> >
> > Has anyone ever tried to create this kind of library from the Octave
> > classes? Wouldn't it a good idea to do so? There aren't any good, free
> > algebra libraries available from the net to my knowledge. Of course, I
> > wouldn't mind doing this (as I need them myself) but some additional
> > documentation on the C++ classes would be practical. Is more available
> > on the structure of the classes and how they inter-relate?
> >
> >
> > Thanks,
> >
> > Jan.
> >
> >
> >
> > -------------------------------------------------------------
> > Octave is freely available under the terms of the GNU GPL.
> >
> > Octave's home on the web:  http://www.octave.org
> > How to fund new projects:  http://www.octave.org/funding.html
> > Subscription information:  http://www.octave.org/archive.html
> > -------------------------------------------------------------
> >
> >
> 
> --
> Dr. Douglas Eck, http://www.idsia.ch/~doug
> Istituto Dalle Molle di Studi sull'Intelligenza Artificiale (IDSIA)
> Neural Networks, Rhythm Perception and Production, Dynamical Systems
> 
>   ------------------------------------------------------------------------
> //Douglas Eck doug at idsia dot ch
> 
> #include <octave/oct.h>
> 
> int main(void) {
>   int sz=20;
>   Matrix m = Matrix(sz,sz);
>   for (int r=0;r<sz;r++) {
>     for (int c=0;c<sz;c++) {
>       m(r,c)=r*c;
>     }
>   }
>   cout << "Hello world! " << endl;
>   cout << m;
> }
> 
> 
> 
>   ------------------------------------------------------------------------
> ##A simple makefile for linking against octave 2.1.35 liboctave
> 
> OPTIMIZATION = -pg -g
> OCTAVE_VERSION=2.1.35
> CC=c++
> CCINCLUDES=-I/usr/include/octave-$(OCTAVE_VERSION) -I/usr/include/octave-$(OCTAVE_VERSION)/octave
> CCFLAGS=-mieee-fp -fno-rtti -fno-exceptions -fno-implicit-templates  $(OPTIMIZATION)
> LD_LIBS=-lblas -loctave -loctinterp -ldl  -lcruft  -lg2c -ltermcap -lhdf5 -lreadline -lkpathsea -lfftw
> LD_PATHS=-L/usr/lib/octave-$(OCTAVE_VERSION) -L/usr/src/octave-$(OCTAVE_VERSION)/kpathsea
> 
> helloWorld: helloWorld.o
>         g++ $(OPTIMIZATION) helloWorld.o -o helloWorld $(LD_PATHS) $(LD_LIBS)
> 
> helloWorld.o: helloWorld.cc
>         g++ -c $(OPTIMIZATION) helloWorld.cc -o helloWorld.o $(CCINCLUDES)
> 
> clean:
>         rm helloWorld.o helloWorld



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
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