[R-sig-eco] Negative Data Error with Decorana in Vegan

[Jari Oksanen]

On 21/07/10 00:37 AM, "Michele Tobias" <tobias.michele at gmail.com> wrote:

> On 7/19/2010 5:49 PM, Gavin Simpson wrote:
>> On Mon, 2010-07-19 at 17:35 -0700, Michele Tobias wrote:

> Thank you for your help, Gavin!  Your suggestions helped me finally
> figure out what the problem was.  It turns out that my data frame had
> the plot names (text) in the first column instead of plot names as the
> row names for the data frame, so the error message didn't quite match
> the problem: text where it shouldn't have been and not negative data.

Michele,

I'm sure that there also were negative data entries because they were found
and reported. However, I changed the order of tests in the devel version of
vegan so that non-numeric data are detected and reported before checking
negative data entries.

This does not stop this kind of reports (and this was not the first one).
When R says that you have non-numeric or negative data while you are "fairly
sure" that you don't have them, the common rule is that you're wrong and R
is right. Check your data to see that it is like you expect it to be. This
is not an issue to argue with computers: they always win.

Cheers, Jari Oksanen