for loop

Thanks for the kind help!
? ? ? ? ? ? ? Hannah

2010/10/14 Brian Diggs <diggsb at ohsu.edu>

?On 10/14/2010 2:53 PM, li li wrote:

Dear all,
? I have a function f(x) ?which return a list as result.

$T1
[1] 0.03376190
$T2
[1] 0.04725
$T3
[1] 0.3796071
$T4
[1] 0.3713452
$T5
[1] 0.4523651
$T6
[1] 0.4575873

? I now find the result for a vector of x values at one time. I want to
store the reuslt
for each xi value in a column of a matrix

x<- seq(0,1, by=0.1)
result<- matrix(0, nrow=6, ncol=length(x))

for (i in 1:length(x)){result[,i]<- f(x[i])}

It is not working. Can some help me.
Thank you very much!
? ? ? ? ? ? ? ? ? ? ? ? Hannah

In order to test my solution, I needed a function that returned something
of the structure you had.

f <- function(x) {
? ? ? ?r <- as.list(rnorm(6))
? ? ? ?names(r) <- paste("T",1:6,sep="")
? ? ? ?r
}

Using that, you can replace the for loop with:

for (i in 1:length(x)){result[,i] <- unlist(f(x[i]))}

The problem is that f returns a list; you can only put a vector in part of
a matrix. ?unlist() takes care of that conversion.

--
Brian S. Diggs, PhD
Senior Research Associate, Department of Surgery
Oregon Health & Science University

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