I have a simple question, but I couldn't find the answer in R manuals.
Assume I have a list:
foo - list()
foo[[1]] - c(1, 2, 3)
foo[[2]] - c(11,22,33)
foo[[3]] - c(111,222,333)
foo
[[1]]
[1] 1 2 3
[[2]]
[1] 11 22 33
[[3]]
[1] 111 222 333
How to use list index to get a vector of, say, the
On 5/16/05, Luke [EMAIL PROTECTED] wrote:
I have a simple question, but I couldn't find the answer in R manuals.
Assume I have a list:
foo - list()
foo[[1]] - c(1, 2, 3)
foo[[2]] - c(11,22,33)
foo[[3]] - c(111,222,333)
foo
[[1]]
[1] 1 2 3
[[2]]
[1] 11 22 33
[[3]]
[1] 111
Its the indexing function written in ordinary function form. That is,
foo[1:2] can be written as [(foo, 1:2)
On 5/16/05, Luke [EMAIL PROTECTED] wrote:
Yes, it works. Althought I can understand the help page of sapply, I
don't know why it works. What is [?
-Luke
On 5/16/05, Gabor
Hi Gabor, thanks a lot. I understand it now. But Andrew's method is
easier for me to understand. Can I extend my question? I have a data
file, every line has such format:
2:102 5:85 ...
The number before colon is data entry index, the number after colon is
data entry value, and other data entries
If you have the data in files in such format, with one entry per line, you
can do something like:
dat - matrix(scan(fileWithData, sep=:), ncol=2, byrow=TRUE)
Then the first column of dat would be the indices, and the second column
would be the values.
Andy
From: Luke
Hi Gabor, thanks a
