> You did not change df$quant - you made a new object called 'subdf'
> containing a column called 'quant' that had only one level. Changing subdf
> has
> no effect on df.
Also, subsetting a factor _intentionally_ does not change the number of levels.
Example:
f <- factor(sample(letters[1:3], 30, replace=TRUE))
f[1] #One element, still three levels
If you want to drop levels, use droplevels() either on the factor or on the
subset of your data frame. Example:
droplevels(f[1]) #One element, only one level
Also worth noting that df is a function.
> df <- data.frame(quant=factor(letters))
looks very like you're assigning a data frame to the function 'df' (density for
the F distribution)
It doesn't, because R is clever. But it's really not good practice to use
common function names as variable names. Too much potential for confusion.
S Ellison
*******************************************************************
This email and any attachments are confidential. Any use...{{dropped:8}}
______________________________________________
[email protected] mailing list -- To UNSUBSCRIBE and more, see
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.
