[R] density(x)

[Prof Brian Ripley]

OK, so sp is a data frame.  Probably you want density(sp$sp) there since 
the single column is already numeric.

It just so happens that truehist does an implicit drop() on a 1-column 
data frame.

On Mon, 5 Jul 2004, Christoph Hanck wrote:

> Hello and thanks for your reply
> 
> Hopefully, my answer arrives at the correct place like that (if not, I am sorry for bothering you, but please let me know...)
> 
> To sum up my procedure (sp is exactly the same thing as spr, I had just tinkered with
> the names while trying sth. to solve this problem)
> 
> > sp<-read.table("c:/ratsdata/sp3.txt", col.names="sp")
> > xd<-density(sp)
> Error in density(sp) : argument must be numeric
> 
> The suggested remedies yield the following
> > str(sp)
> `data.frame':   195 obs. of  1 variable:
>  $ sp: int  11 10 10 12 25 22 12 23 13 15 ...
> > xd<-density(as.numeric(sp))
> Error in as.double.default(sp) : (list) object cannot be coerced to double
> 
> Hence, it does not seem to be a factor. Declaring it as numeric gives another error
> message, on which I haven't yet found any help in Google/the archive.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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