[R] factors

Gabor Grothendieck ggrothendieck at gmail.com
Fri May 6 00:45:47 CEST 2011


On Thu, May 5, 2011 at 6:28 PM, J <jonsleepy at gmail.com> wrote:
> Hi, I'm requesting you don't berate me for asking this question:
>
> I clearly don't have the gist of factors.
>
> I have two dataframes, A and B.
>
> Each of them has a column containing strings (they're labels).
>
> I want to, one-by-one in a loop, compare the particular string in an entry from dataframe A to an entry in B, to see if they're the same.
>
> The problem, when posing the question:
> searchID1 <- A[['label']][i]
> possMatch1 <- B[['label']][j]
> searchID1 == possMatch1
>
> I get the error:
> Error in Ops.factor(searchID1, possMatch1) :
>  level sets of factors are different
>
> I presume this is because the set of possible values in the 'labels' columns, respectively in A and B, differ.  In my case, I'm not interested in this at all; I just want to compare individual entries from the two dataframes in a pair-wise fashion.
>
> Can I strip the "factors" associated with the entries?  Is there a better way?
>

Assuming you read them in using read.table, use
read.table(...whatever..., as.is = TRUE) and then it will read them as
character strings rather than factors.


-- 
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com



More information about the R-help mailing list