Re: Algorithmic Differentiation in Octave

[Brad Bell]

Did your run the following command ?
    make check_lib_octave
(see same question below)

On 02/04/2017 05:48 AM, Olaf Till wrote:
> On Sat, Jan 28, 2017 at 09:42:43AM +0100, Olaf Till wrote:
> > For finding an overall way to fit this into Octave, I still have to
> > find out about some issues in your interface which are not clear to
> > me. But before asking, I'd like to give it a try, making it compile
> > and experimenting with it a bit. Since I have currently some other
> > things on my schedule, I guess it'll take a week.
> I havn't come very far. The cppad library, compiled according to the
> instructions at
>
> https://www.coin-or.org/CppAD/Doc/cmake.htm
>
> with
>
> cd build
> cmake -G "Unix Makefiles" -D cppad_prefix=/usr/local ..
>
> with 'make install' only installs headers, no library. And I find no
> library even under the build/directory.
Cppad is a header only package. There is are a few library's that will 
install if you choose certain options, but the headers are all that is 
needed by cppad_swig. You can run a check of CppAD for your particular 
machine with the following command
    make check
see
    https://www.coin-or.org/CppAD/Doc/cmake_check.xml

Note that the cppad_swig package does provide a C++ AD object library; 
e.g., see
http://www.seanet.com/~bradbell/cppad_swig/a_fun_jacobian_xam.cpp.htm

> swig-cppad compiled an oct-file, after fiddling with Octaves include
> files. (BTW: Instead of `octave-config -p INCLUDEDIR`, use `mkoctfile
> -p INCFLAGS`, yielding 2 include dirs, with '-I' already prepended.
Thanks, I will give this a try.
> swig-cppad compiled this although no cppad library was present
> anywhere, and not even the cppad headers were present at this time
> (and I don't find them in swig-cppad either)! The resulting oct-file,
> according to 'ldd', referenced nothing which looked like a cppad
> library, of course. And it segfaulted at the time of loading into
> Octave.
See the heading Testing on
    http://www.seanet.com/~bradbell/cppad_swig/cppad_swig.htm
When you run
    bin/run_cmake.sh
there will a list of available make commands (for your configuration).

Did your run the following command ?
    make check_lib_octave
This should build all the example *.m files, the octave swig interface, 
and run the tests.
Setting verbose to true in bin/run_cmake.sh (before running it) may help.

No install is yet available because I figure that should be wrapped with 
the special code (like matrix multiply in Octaves case) for each language.
> So I can only give 'theoretical' notes now.
>
> Let's assume swig-cppad worked as expected. Then, if we took it
> unchanged, we'd have to define a wrapper class around it. Doing this
> in iterpreted Octave code would yield matrix operations which are too
> slow.
I thought that Octave would automatically generate matrix operations in 
C++ that used the overloaded classes (as numpy does for python) ?

> I think the best bet would be to generate an Octave type at the c++
> level (similar to what swig-cppad currently does) which interfaces to
> cppad and already contains overloading of matrix operations.
>
> If the latter is done, I would not like to do it with swig, but rather
> try it directly with Octaves API. And the build system of swig-cppad
> would have to be changed anyway, IMHO, to make it distributable as an
> Octave package.ld
I defined a very lightweight (and I think efficient) interface from the 
Cppad Swig library to any language. I figured that this would greatly 
reduce the work involved in make taped AD available in not only 
available in python, but other languages as well.
> This would be rather a long term project for me (but maybe others
> would be faster). I have difficulties in deducing from swig-cppad the
> interaction with the cppad interface. I'd have to learn how to
> interface with cppad from the cppad documentation.
>
> Problems are that cppad currently installs no library for me (see
> above), and that cppad doesn't seem to be available in current Debian
> (i.e. only the headers are available there).
See
   https://tracker.debian.org/pkg/cppad
> Olaf