[R] Convert data frame entries to numbers

[joris meys]

2 problems :
test seems to be a data frame or list with one variable. So you have
to specify :
as.numeric(test$classcol)

But this will make the internal factor levels the real values, not the
numbers you specified. What you need, is

as.numeric(as.character(test$classcol))

Cheers
Joris

On Mon, Oct 19, 2009 at 3:07 PM, John <josip.2000 at gmail.com> wrote:
> Hello,
>
> I figure this is quite a simple problem really, but since I'm quite
> new to R I need to ask:
>
> If I have a data frame:
>
> str(test) :
> $ classcol: Factor w/ 3 levels "1","2","3"
>
> How do I convert the entries in this column to numbers. I.e., I want
> to be abl to do simple calculations like test[1,the_column] - test
> [2,the_column] without errors.
>
>
> as.numeric(test) yeilds the error "object cannot be coerced to type
> 'double'"
>
>
> Thanks!
> John
>
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