Hi, I spent the last few days porting the well known DOP853<http://www.unige.ch/~hairer/software.html>integrator to Julia. The process was quite smooth and I have implemented the core functionality. However when I run my reference case, a numerical solution of the two-body problem, I get the following timings:
- *Fortran* (gfortran 4.8.2 no optimizations): *~1.7e-5s* - *Julia* (master, looped): *~1.3e-3s* - *Julia* (master, vectorized): *~1e-3s (!) * I have posted the Julia code and the Fortran reference in this Gist<https://gist.github.com/helgee/8019521>. The computationally expensive part seems to be contained in the *dopcore *or *dopcorevec *function, respectively. What I really do not understand is, why the vectorized expressions seem to run faster or rather what I am doing wrong here. Any ideas or suggestions? Many thanks in advance! Helge
