R badly lags matlab on performance?
Ajay Shah wrote:
As for jit and Ra, that was immediate reaction too but I found that jit does
not help on your example. But I concur fully with what Ben said --- use the
tool that is appropriate for the task at hand. If your task is running for
loops, Matlab does it faster and you have Matlab, well then you should by all
means use Matlab.
A good chunk of statistical computation involves loops. We are all happy R users. I was surprised to see that we are so far from matlab in the crucial dimension of performance.
this list has a tradition of encouraging users to use apply&relatives
instead of for loops (and to use vectorised code instead of both).
compare the following for n = 10^6 and n = 10^7:
x = 1:n
system.time({for (i in 1:n) x[i] = x[i] + 1})
x = 1:n
system.time({x = sapply(x, `+`, 1)})
vQ