Programming in C++ - Lapack++ or TNT

[bernoulli]

Hi. I'm interested in making some programs in mathematics/signal analysis in C++, and I cannot figure out what packages to use, lapack++ or tnt? Any one else? What about packages for Fourier analysis?

[Joeb454]

What do you want to use the packages for? For writing the code? If so the standard text editor in Ubuntu supports C/C++ syntax highlighting :)

[sdennie]

I've not looked at the BLAS/LAPACK interfaces for C++ (or TNT at all) but, if you are even vaguely concerned with performance, I'd be very wary of any OO interface to those libraries. As for FFTs, I believe they are included in LAPACK (at least they are/were in Suns implementation).

Edit:
Oh, FFT stuff is included in FFTPACK I think. That just happens to come with many vendors BLAS/LAPACK packages.

[Golem XIV]

You may want to take a look at numerical recipes (http://www.nr.com/)

[bernoulli]

Yes, I want to write actual C++ code to perform certain tasks in mathematics and signal analysis.

I've done tutorials on C++ and I think I have the basic stuff in order. The problem comes when I want to do some scientific programming. I'm not sure which packages (or is it libraries?) to use, and how to install some of them.

[sdennie]

If you are fairly new to C++ and Ubuntu, I would recommend going to System->Administration->Synaptic Package Manager and searching for lapack. Look for the packages with the Ubuntu icon by them (excluding the two python packages) and install them. I think that will give you the standard FORTRAN versions of BLAS/LAPACK with C interfaces to them. Those interfaces should be callable from C++ but, without the likelihood of shooting yourself in the foot with a higher level interface to perfectly good function calls/data structures.

[bernoulli]

I've decided to go for IT++, which is supposed to be an alternative to Lapack++. On first glance it looks a bit similar to Matlab-notation.

I downloaded and installed IT++ through the "Synaptic Package Manager", but I can not seem to compile simple test programs. If I try this straight forward line:

g++ -o test-itpp test-itpp.cpp
I will get errors like

test-itpp.cpp:(.text+0x10f): undefined reference to `itpp::Vec<double>::Vec(int,
itpp::Factory const&)'

When I try to follow the first section on their webpage (http://itpp.sourceforge.net/current/linking.html), i.e. with the command:

g++ `pkg-config --cflags itpp` -o test-itpp test-itpp.cpp `pkg-config --libs itpp`

I get this:

/usr/bin/ld: cannot find -lcblas
collect2: ld returned 1 exit status

Now, I got this earlier too, with -llapack and -lfftw3. I solved this by installing these again. I just looked in the folder /usr/lib/ and saw now that I have the files liblapack.la and libfftw3.la (and .a), but I do not have this with cblas. I only have libcblas.so.3 and libcblas.so.3.0 (all are shared libraries). Does anyone have any ideas on what I can do? I can't find cblas in "Synaptic Package Manager", but these should have been installed at the same time with IT++, right? I remember there was many other packages that were installed at the same time, including fftw3.

I guess I'm to used to things working right out of the box.

[bernoulli]

Hmm. It looks like it works now after I installed "atlas3-base-dev" and "atlas3-headers". I already had "atlas3-base".

I will have to test it some more later...

[jeremytaylor]

If you're looking for an easy to use OO matrix library then you might like to try newmat
http://www.robertnz.net/nm_intro.htm

You'll drop a few performance points but not as many as you might think.

Jeremy

[bernoulli]

Thanks, but for now I'm pretty happy with IT++.