[R] Re :argument is not numeric or logical

[David Winsemius]

On May 2, 2010, at 3:27 PM, Mohan L wrote:

>
>
> >as.numeric(assame$Login)  //convert to numerics
>
>
> NOOOOooooooo. You did not do what what I suggested earlier. Do not  
> reach for your keyboard in the R console until you have read the FAQ  
> section regarding converting factors to numeric. If you don't want  
> to read the FAQ
>
> Hi David,
> Now I understand the trick :
>
> as.numeric(as.character(Login))
>
>
> > avglog <-  
> with(assame,tapply(as.numeric(as.character(Login)),stdate,mean))> >  
> avglog
> 01/11/09 00:00 02/11/09 00:00 04/11/09 00:00 05/11/09 00:00 06/11/09  
> 00:00
>       22.04866       16.65358       15.84970       16.58600        
> 16.20743
> 07/11/09 00:00
>       18.52379
>
> But still it will not work :
>
> > avglog <- with(assame,tapply(as.numeric(levels(Login) 
> [as.integer(Login)]),stdate,mean))

Sometimes using with(. , .) does not work when the variable name is  
buried deep in a nested set of functions. Furthermore mean needs an  
na.rm argument if, as I suspect, you now have some some NA's in the  
new variable. What happens when you:

assame$Login.num <- as.numeric(as.character(assame$Login))
avglog <- with(assame,  tapply(Login2, stdate, mean, na.rm=TRUE) )
avglog


Untested of course since we STILL have no reproducible example. Had  
you used dput on head(sample, 40) or head(sample2, 40) or head(assame,  
40) we would not still be here guessing at what you really are working  
with.

-- 
David.

> Error in tapply(as.numeric(levels(Login)[as.integer(Login)]),  
> stdate,  :
>   arguments must have same length
>
>
> Thanks & Rg
> Mohan L
>
>
>
>

David Winsemius, MD
West Hartford, CT