while octave is a matlab clone for gnu/linux systems it does not offer much help to those who want to harness the speed of c/c++ programming. however development time is rather large specially when open source and standard scientific libraries are not available.
the usual trend is to test out an idea in a rapid development environment like matlab/octave/scilab and then code it in c/c++ if speed is an issue as has often happened with me. if a library existed that provided all (?) matlab functionality to a researcher then he/she could concentrate more on doing the research rather than having to invest time in developing the software tools needed for the research. after all there is no point in reinventing the wheel.
also i feel there is a need for a scientific computing framework in which the basic element is a tensor/matrix, as is the case with matlab. yes i have been using gsl/slicot for some time but working with gsl is not an “easy” task. but thank god for gsl and other open source or free libraries or else i would have been in a big soup.
as far as my understanding goes its possible to use c/c++ in matlab/octave but they usually require one to call c/c++ routines from inside of matlab/octave. however my needs are to be able to use matlab/octave from c/c++ programs. moreover if i could help it i want to rely and use free and open source software only. this is a MUST for researchers in countries like india.