aggregate function

Here is an example using 'data.table'"
x <- read.table(text = "param       case1
+ 1               a
+ 2               b
+ 2               c
+ 2               d
+ 3               e
+ 4               f", header = TRUE, as.is = TRUE)
require(data.table)
x <- data.table(x)
x[
+     , list( case1 = paste(case1, collapse = ','))
+     , by = param
+  ]
     param case1
[1,]     1     a
[2,]     2 b,c,d
[3,]     3     e
[4,]     4     f

Hi
I have a data frame with values in following format.

param ? ? ? case1
1 ? ? ? ? ? ? ? a
2 ? ? ? ? ? ? ? b
2 ? ? ? ? ? ? ? c
2 ? ? ? ? ? ? ? d
3 ? ? ? ? ? ? ? e
4 ? ? ? ? ? ? ? f

how to use aggregate so that it I only one row for each 'param' value.

the output for the above input should be

param ? ? case1
1 ? ? ?a
2 ? ? ?b,c,d
3 ? ? ?e
4 ? ? ?f

Thanks
M

--
-------------
Mary Kindall
Yorktown Heights, NY
USA

? ? ? ?[[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.

aggregate function

Thread (9 messages)