Sohail Somani wrote:
On Tue, 20 Nov 2007 15:24:42 +0000, nisha kannookadan wrote:
Hi everybody
Im a quite new boost user and I wonder, why C++ Program is so slow.
I wrote a program, and I have the same program in Matlab, I expected that my C++ version is much faster, but its not.
I use matrices, vectors, matrix- and vector proxies. Do some solving and compute calculations with prod, element_div, etc..
Is boost in general slower than matlab, should I use something else?
Id be real happy about any help.
Matlab uses some highly optimized matrix operations libraries (BLAS/ LAPACK for example.) I assume you use Boost uBLAS which is quite a good library but it has nowhere near the amount of investment put into it as does Matlab.
uBlas has bindings for various BLAS libraries in the sandbox which speed things up quite a bit. Also if your program has debug settings turned on then uBlas will be *very* slow, it's only when you turn on all your compiler's optimisations (and maybe define NDEBUG) that uBlas gets up to speed. There is also a dedicated mailing for uBlas users will will likely be more helpful than this one :-) HTH, John.