Interfacing Ada with C
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From: Dmitry A. Kazakov on 25 Jul 2010 16:04 On Sun, 25 Jul 2010 12:28:44 -0700 (PDT), Ada novice wrote: > Yes you're right. I only thought that imsl.ad(b,s) should be compiled > first. It will as needed, i.e. when used in a project that produces something. At some point later when you decide to turn your bindings into a library (object/static and/or shared), you could change the IMSL project so that it would produce that library. Then it will become compilable. > Thank you very much all of you especially Dmitry and Simon for your > very kind help. I'll need to study the code that you provided. You are welcome. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de
From: Simon Wright on 25 Jul 2010 19:21 Ada novice <posts(a)gmx.us> writes: > Many thanks for all your inputs. I'll give you an example. Say we want > to compute the eigenvalues of this 3 X 3 matrix. The code in C (using > the IMSL library) is as follows: [...] > What would the best way to interface this with Ada? The elements of my > matrix will be formed in Ada, then the matrix will be passed to C to > calculate the eigenvalues and then the latter passed back to Ada. The > size of my matrix will be fixed say 3 x 3. As a novice in Ada, I would > like to learn good programming practice and the best way is to use > codes and learn from experts here in Ada. I've encoded a general complex eigenvalues function, interfacing to the LAPACK procedure zgeev, starting from a demo at http://www.physics.oregonstate.edu/~rubin/nacphy/lapack/codes/eigen-c.html & copying bits and pieces from within the GNAT implementation of Ada.Numerics.Generic_Complex_Arrays. Find it at http://public.me.com/simon.j.wright (folder numerics). NB1 LAPACK is a Fortran code, hence the need to transpose the matrix. NB2 the compilation gives warnings .. $ gnatmake test_zgeev.adb gcc -c test_zgeev.adb test_zgeev.adb:9:06: warning: "Interfaces.Fortran.BLAS" is an internal GNAT unit test_zgeev.adb:9:06: warning: use of this unit is non-portable and version-dependent test_zgeev.adb:10:06: warning: "Interfaces.Fortran.LAPACK" is an internal GNAT unit test_zgeev.adb:10:06: warning: use of this unit is non-portable and version-dependent gnatbind -x test_zgeev.ali gnatlink test_zgeev.ali $ However, (a) one could always write ones own versions, (b) the results are the same with GNAT GPL 2010 and GCC 4.5.0, (c) the output looks good (from your inputs) .. $ ./test_zgeev 2.00000000000000E+00 4.00000000000000E+00 2.00000000000000E+00 -4.00000000000000E+00 9.99999999999996E-01 2.07319734774360E-16 I get the strong impression that to know what the arguments of the BLAS & LAPACK subprograms are you have to buy the book or read the code! This all worked without any need for additional link-time arguments on Mac OS X, but YMMV on Windows. If not, I *think* that if you with Ada.Numerics.Long_Complex_Arrays (no need to use anything from it) that would be enough to bring in the necessary libraries.
From: John B. Matthews on 25 Jul 2010 21:24 In article <m2iq43rvv1.fsf(a)pushface.org>, Simon Wright <simon(a)pushface.org> wrote: > I've encoded a general complex eigenvalues function, interfacing to the > LAPACK procedure zgeev, starting from a demo at > http://www.physics.oregonstate.edu/~rubin/nacphy/lapack/codes/eigen-c.html > & copying bits and pieces from within the GNAT implementation of > Ada.Numerics.Generic_Complex_Arrays. > > Find it at http://public.me.com/simon.j.wright (folder numerics). Exemplary! > NB1 LAPACK is a Fortran code, hence the need to transpose the matrix. > > NB2 the compilation gives warnings .. > > $ gnatmake test_zgeev.adb > gcc -c test_zgeev.adb > test_zgeev.adb:9:06: warning: "Interfaces.Fortran.BLAS" is an internal GNAT unit > test_zgeev.adb:9:06: warning: use of this unit is non-portable and version-dependent > test_zgeev.adb:10:06: warning: "Interfaces.Fortran.LAPACK" is an internal GNAT unit > test_zgeev.adb:10:06: warning: use of this unit is non-portable and version-dependent For convenience, the warnings may be suppressed: pragma Warnings("I"); -- John B. Matthews trashgod at gmail dot com <http://sites.google.com/site/drjohnbmatthews>
From: Ada novice on 26 Jul 2010 09:40 On Jul 25, 10:04 pm, "Dmitry A. Kazakov" <mail...(a)dmitry-kazakov.de> wrote: > At some point later when you decide to turn your bindings into a library > (object/static and/or shared), you could change the IMSL project so that it > would produce that library. Then it will become compilable. > Would you be kind enough to elaborate on your above comments a little more? Thanks YC
From: Ada novice on 26 Jul 2010 09:52
On Jul 26, 1:21 am, Simon Wright <si...(a)pushface.org> wrote: > I've encoded a general complex eigenvalues function, interfacing to the > LAPACK procedure zgeev, starting from a demo athttp://www.physics.oregonstate.edu/~rubin/nacphy/lapack/codes/eigen-c... > & copying bits and pieces from within the GNAT implementation of > Ada.Numerics.Generic_Complex_Arrays. > > Find it athttp://public.me.com/simon.j.wright(folder numerics). Thank you very much for your commendable efforts. This is a very good example to demonstrate how Ada can be binded with LAPACK. >(b) the results > are the same with GNAT GPL 2010 and GCC 4.5.0, (c) the output looks good > (from your inputs) .. > > $ ./test_zgeev > 2.00000000000000E+00 4.00000000000000E+00 > 2.00000000000000E+00 -4.00000000000000E+00 > 9.99999999999996E-01 2.07319734774360E-16 I have Win XP and gcc (GCC) 4.3.6 20100603 for GNAT GPL 2010 (20100603). I get slightly different output: 1.99999999999999E+00 3.99999999999999E+00 2.00000000000000E+00 -4.00000000000000E+00 1.00000000000000E+00 -3.45920620709768E-16 Your GCC version is more recent than mine. Maybe this is causing the discrepancies or maybe it's because of your different OS. Did you install your GCC separately? I got mine bundled with the GNAT GPL 2010. >I get the strong impression that to know what the arguments of the BLAS >& LAPACK subprograms are you have to buy the book or read the code! On a side note, there's this book: Handbook for Automatic Computation: Volume 2: Linear Algebra (Grundlehren der mathematischen Wissenschaften) by John H. Wilkinson, C. Reinsch, Alston S. Householder, and Friedrich L. B which has lots of test matrix cases to check whether algorithms are performing correctly. > This all worked without any need for additional link-time arguments on > Mac OS X, but YMMV on Windows. If not, I *think* that if you with > Ada.Numerics.Long_Complex_Arrays (no need to use anything from it) that > would be enough to bring in the necessary libraries. It works fine on Windows too with anything to add. And I get the same compilation warnings. YC |