[R] convert numeric variables to factor

[S Ellison]

> From: R-help [mailto:r-help-bounces using r-project.org] On Behalf Of Saif Tauheed
> After that I have the following error:
> 
> cols<- c("GrMM", "RELG", "CASTE1", "SECTOR", "SECTOR4","AGE", "MARITAL",
> "JOBSTATUS", "ENG", "EDU", "PARENT_EDU", "MASSMEDIA_F",
> "MASSMEDIA_M", "HomeComputer", "HomeInternet")
> > for (I in cols) {data.frame[,i]= as.factor(data.frame[,i])}
> 
> 
> Error in sort.list(y) : 'x' must be atomic for 'sort.list'
> Have you called ‘sort’ on a list?
> 

First, please post reproducible examples; your code will not run in anyone else's session (for example you have not shown where the data frame comes from), and if the code does not generate the error message reproducibly, noone can tell you exactly why it happens

Second, please _follow_ the posting guide and work through the suggested steps before posting a question to this list. An internet search for this error would have told you what causes it.

Finally: 
- Your loop will not work because your loop variable is I and the index is i; they are different in R. You'll just update the same column (i) lots of times, assuming i is defined.

- The error message arises from a call to factor() in as.factor(). It tells you that the column being converted is not a simple vector. That in turn tells me that you have not constructed your data frame correctly. I can't tell you what you did wrong there. 

- As another poster has said, data.frame is the name of a function - one that construicts a data frame. R can often tell which you want, but it is never safe to use the name of a function as the name of a data object. Use a different name for your data frame.

S Ellison


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