summation sign
On Oct 27, 2012, at 01:34 , sffarooqi wrote:
Hi all,
I have a very quick question on how to use the summation sign in R for the
function.
Here?s a basic example: the function is sum(i=1 to 5)log(1-xi^2)
Id be grateful if someone knows how to do this without writing it out 5
times - I am looking sth along the lines of the following:
computeR <- function(x)
{
return (-sum(log(1-x^2))
}^
thank you vm in advance!
You pretty much did it already:
x <- c(.5,.6,.7,.4,.8) -sum(log(1-x^2))
[1] 2.603318 I.e., just have x as a vector of length 5 and the rest is done automagically. (And, BTW, you don't need return() in a function like that in R, the return value is the value of the last expression.)
Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com