as.matrix() will not help here. I will get the same error message. And also, I don't need correlation matrices. I simply need a vector of correlations. I will show you some code and data I am using.
Here you can see my main dataframe: > head(test) industry date testvar retf1 1 Industrials 2004-12-31 1174382477 -0.02240908 2 Industrials 2005-01-31 1101039133 0.08080221 3 Industrials 2005-02-28 1211723486 0.05646877 4 Industrials 2005-03-31 1253428861 -0.05743186 5 Industrials 2005-04-30 1152846793 -0.02928415 6 Industrials 2005-05-31 1070386589 0.05865941 Now I want to take column "industry" or "date" or both - whatever - as grouping columns for correlations between testvar and retf1 as follows: *> numbers <- test[,c("testvar","retf1")]* > head(numbers) testvar retf1 1 1174382477 -0.02240908 2 1101039133 0.08080221 3 1211723486 0.05646877 4 1253428861 -0.05743186 5 1152846793 -0.02928415 6 1070386589 0.05865941 *> groups <- test[,"industry"]* > head(groups) [1] "Industrials" "Industrials" "Industrials" "Industrials" "Industrials" [6] "Industrials" > head(unique(groups)) [1] "Industrials" "Telecommunications" "Financials" [4] "Utilities" "ConsumerGoods" "OilandGas" *AND NOW:* *> aggregate(numbers,by=list(groups),FUN="cor")* Fehler in FUN(X[[1L]], ...) : supply both 'x' and 'y' or a matrix-like 'x' So my desired output is a vector of correlations between subsets of x = "testvar" and y = "retf1". The length of the resulting vector will be length(unique(groups)). I think this draws a clearer picture to you. Sorry for not precisely pointing it out in my first post. Thanks and Regards! -- View this message in context: http://r.789695.n4.nabble.com/Using-Aggregate-with-FUN-arguments-which-require-more-than-one-input-variables-tp4303936p4306048.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.