I seem to be running into the same problem reported in https://stat.ethz.ch/pipermail/r-help/2010-November/258265.html
I cannot seem to transform a dataset from long to wide using reshape2. Clearly I am missing something very simple but a look at the manual and the reshape paper in JSS does not suggest anything. Any advice would be welcome ===========================load rehape2==================== library(reshape2) ========================Working example=========================== # Example from above URL dat <- read.table(textConnection('Subject Item Score "Subject 1" "Item 1" 1 "Subject 1" "Item 2" 0 "Subject 1" "Item 3" 1 "Subject 2" "Item 1" 1 "Subject 2" "Item 2" 1 "Subject 2" "Item 3" 0'), header=TRUE) closeAllConnections() acast(dat, Subject~Item) # Seems fine =====================My attemp=========================== # set.seed(1) mydata <- data.frame( x=sample(LETTERS[23:26],100, replace=TRUE), y=rnorm(100, mean=2), id=sample(letters[1:4], 100, replace=TRUE)) acast(mydata , id ~ x) # not so fine ================================================================= produces this : Using id as value column: use value_var to override. Aggregation function missing: defaulting to length W X Y Z a 7 5 5 7 b 6 9 6 12 c 1 4 5 6 d 6 14 5 2 Why does reshape2 think it needs an aggregation function here> Thanks ______________________________________________ R-help@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.