Using R version 2.4.1 (2006-12-18) on Windows, I have a dataset which resembles
this:
id att1 att2 att3
1 1 1 0
2 1 0 0
3 0 1 1
4 1 1 1
ratings <- data.frame(id = c(1,2,3,4), att1 = c(1,1,0,1), att2 = c(1,0,0,1),
att3 = c(0,1,1,1))
I would like to get a cross tab of counts of co-ocurrence, which might resemble
this:
att1 att2 att3
att1 2 1
att2 2 2
att3 1 2
with the hope of understanding, at least pairwise, what things "hang together".
(Yes, there are much, much better ways to do this statistically including
clustering and binary corrected correlation, but the audience I am working with
asked for this version for a specific reason.)
(Later on, I would also like to convert to percentages of the total unique pop,
so the final version of the table would be
att1 att2 att3
att1 50% 25%
att2 50% 50%
att3 25% 50%
But I can do this in excel if I can get the first table out.)
I have tried the reshape library, but could not get anything resembling this
(both on its own, as well as feeding in to table()). (I have also played with
transposing and using some comments from this list from 2002 and 2004, but the
questioners appear to assume more knowledge than I have in use of R; the
example in the posting guide was also more complex than I was ready for, I'm
afraid.)
Sample of some of my efforts:
library(reshape)
melt(ratings,id=c("id"))
ds1 <- melt(ratings,id=c("id"))
table(ds1$variable, ds1$variable) # returns only rowcounts, 3 along diagonal
xtabs(formula = value ~ ds1$variable + ds1$variable , data=ds1) # returns only
a single row of collapsed counts, appears to not allow 1 variable in multiple
uses
I suspect I am close, so any nudges in the right direction would be helpful.
Thanks much, Michael
PS: www.rseek.org is very impressive, I heartily encourage its use.
[[alternative HTML version deleted]]
______________________________________________
[email protected] 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.
