[R] make a triple summation more efficient

kathie kathryn.lord2000 at gmail.com
Sat Nov 15 17:39:48 CET 2008

Dear R users... 

I made the R-code for this triple summation computation 


Here is my code..

x=seq(.1,1,.1); l=10
y=seq(1,10); m=10
z=seq(.1,1,.1); n=10

sum(sapply(1:l, function(i) {sum(sapply(1:m, function(j) {sum(sapply(1:n,
function(k){exp(x[i]*y[j]*z[k]  )/gamma(y[j]+1)}))^(1.5)  }))}))


In fact, this is a part of optimization. I guess if it is vectorized, then
the running time could be shortened.

How could I vectorize this? or any suggestion will be greatly appreciated.

Kathryn Lord
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