[R] Error

[rex.dwyer at syngenta.com]

I have to agree that it's pretty hard to take something that works and figure out why it doesn't work :)
The only other suggestion is that sometimes I find that this sort of error goes away if I add "drop=FALSE" to the subsetting, and, if so,  that usually lets me figure out why.

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Duncan Murdoch
Sent: Sunday, February 27, 2011 5:52 AM
To: mathijsdevaan
Cc: r-help at r-project.org
Subject: Re: [R] Error

On 11-02-26 8:26 AM, mathijsdevaan wrote:
> Mean doesn't work either... I understand that the message "replacement has 0
> items, need 37597770" implies that the function is not returning any values,
> but I don't understand why then this is not the case in the example.
>
> DF = data.frame(read.table(textConnection("    A  B  C  D  E
> 1 1  a  1999  1  0
> 2 1  b  1999  0  1
> 3 1  c  1999  0  1
> 4 1  d  1999  1  0
> 5 2  c  2001  1  0
> 6 2  d  2001  0  1
> 7 3  a  2004  0  1
> 8 3  b  2004  0  1
> 9 3  d  2004  0  1
> 10 4  b  2001  1  0
> 11 4  c  2001  1  0
> 12 4  d  2001  0  1"),head=TRUE,stringsAsFactors=FALSE))
>
> DF = DF[order(DF$B,DF$C),]
>
> #first option - works fine in example and my target data frame
> DF$F = ave(DF$D,DF$B, FUN = function(x) cumsum(x)-x)
> DF$G = ave(DF$E,DF$B, FUN = function(x) cumsum(x)-x)
>
> #second option - works fine in example but not in my target data frame
> foo<- function(x)
>       {
>       unlist(lapply(x, FUN = function(z) cumsum(z) - z))
>       }
> n<-ave(DF[,c(4:5)],DF$B,FUN = foo)
>
> Why is this second option not working in my target data frame (which is much
> bigger than the example)?

Presumably something is different about it.  I don't see how you expect
people to debug your problem when you don't show it.

If you want help, you need to give us an example that shows the error.
Start with your large dataset, and shrink it as much as possible, but
not so much that the error goes away.  (I suspect when you do this,
you'll end up seeing your error yourself.  But maybe not.)

Duncan Murdoch

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.




message may contain confidential information. If you are not the designated recipient, please notify the sender immediately, and delete the original and any copies. Any use of the message by you is prohibited.