Hello I want to keep track of my units in the data frame. I have been advised in the past on this list to create a new "units" attribute of the data frame and keep the units strings there. It works fine as long as I don't manipulate the data frame.
Here's an example: -------------CODE BEGIN ----------------------- df1 <- data.frame(x = 1:10, y = runif(10)) attr(df1,"units") <- c("s", "kg") attr(df1,"units") df1 df2 <- data.frame(z1 = 10*runif(10), z2 = 20*runif(10)) attr(df2,"units") <- c("Pa", "kV") attr(df2,"units") df2 df3 <- cbind(df1,df2) df3 attr(df3,"units") -------------CODE END----------------------- The last line returns NULL. So I got my two data frames nicely bound in a third, but I lost my units along the way. I can easily write my own function "cbinddfwunits" to bind the data frames with the units, but I am curious as what are the rules that govern this unexpected R behaviour. I would definitely expect that if the two objects have similar properties, then these properties should not be lost during object manipulation, but R proves me wrong ... If someone could explain the logic I'll be grateful. Regards, TL ______________________________________________ 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.