JuliaLang/julia — comment on commit 1abf6194aabd5afd5b0c923707deb59537ac5ecc
File:  line 0
By JeffBezanson:

V8 is very impressive...they beat numpy at this even though numpy calls C for all the inner loops.

An interesting point is that if you manually wrote out the loops for the concat, trace, etc. in julia as written here, we would probably get faster. Of course we should in no way do this. Just part of the strangeness of benchmarking languages against each other.