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

[Michele Tobias]

On 7/21/2010 12:43 AM, Jari Oksanen wrote:
> 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
>
>    
Jari,
Thank you for your help.  I appreciate your willingness to address 
confusion.  I did not mean to imply there was anything wrong with the 
code, only that something novel seems to be happening when certain data 
is imported into R that originated in an SQL database.  Maybe there is 
something caused by the RSQL package that caused my problem.  I will 
keep working with both packages and if I repeat the same issue, I will 
send you more information to see if you agree.  Thanks again!

best,
Michele

-- 
Michele Tobias

PhD Candidate
Geography Graduate Group
University of California, Davis

mmtobias at ucdavis.edu
http://ggg.ucdavis.edu/student/michele-m-tobias
http://ucdavis.academia.edu/MicheleTobias