[julia-users] Code optimization

[Dash Khash]

Hi, 
Intrigued 
by https://github.com/jesusfv/Comparison-Programming-Languages-Economics, I 
did a little exercise 

function valuefnc(x, V)
  n=length(x)
  a=0.1;
  b=0.9;
  out=zeros(n);
  for(i=1:n)
    out[i]=maximum(log((1 + x[i]^a) .- x) .+ b*V[i]);
  end
  out
end


And for the grid x=[1:10000]/10000, a single round of calculation takes 
around 3 secs on my notebook. I thought it would be instantaneous. 

n=length(x)
V0=zeros(n)
V1=valuefnc(x, V0)

@elapsed V2=valuefnc(x, V1) 


Similar implementation in R takes about 2.5 secs. 

 sapply(1:length(x), function(i){max(log(1+x[i]^a - x) + b*V[i])})


What am I doing wrong here? I expected Julia would be faster by several 
factors, but I am completely blind to code optimization in Julia.

Thanks