I've never heard of a comprehensive port of matlab functionality to C++. That being said, almost everything matlab does exists within a C/C++ library somewhere, some off the top of my head:
- LAPACK, BLAS, you already mentioned these, and there are a few good implementations, the most notable (free) one being ATLAS.
- FFT is implemented in matlab via the fftw library
- There are loads of fast open-source image libraries out there, ie. interpolation, filtering.
- There are really good OOP matrix libraries out there, boost has a nice one.
After that, well figure out what you need and there is a good chance someone has implemented it in C/C++.
