Matrix classes in c++

Question

I'm doing some linear algebra math, and was looking for some really lightweight and simple to use matrix class that could handle different dimensions: 2x2, 2x1, 3x1 and 1x2 basically. I presume such class could be implemented with templates and using some specialization in some cases, for performance. Anybody know of any simple implementation available for use? I don't want "bloated" implementations, as I'll running this in an embedded environment where memory is constrained.

Thanks

Answer 1

You could try Blitz++ -- or Boost's uBLAS

Answer 2

std::valarray is pretty lightweight.

Answer 3

I use Newmat libraries for matrix computations. It's open source and easy to use, although I'm not sure it fits your definition of lightweight (it includes over 50 source files which Visual Studio compiles it into a 1.8MB static library).

Answer 4

CML matrix is pretty good, but may not be lightweight enough for an embedded environment. Check it out anyway: http://cmldev.net/?p=418

Answer 5

I for one wasn't able to find simple enough library so I wrote it myself: http://koti.welho.com/aarpikar/lib/

I think it should be able to handle different matrix dimensions (2x2, 3x3, 3x1, etc) by simply setting some rows or columns to zero. It won't be the most fastest approach since internally all operations will be done with 4x4 matrices. Although in theory there might exist that kind of processors that can handle 4x4-operations in one tick. At least I would much rather believe in existence of such processors that than go optimizing those low level matrix calculations. :)

Answer 6

How about just store the matrix in an array, like

2x3 matrix = {2,3,val1,val2,...,val6}

This is really simple, and addition operations are trivial. However, you need to write your own multiplication function.