Hi,
Maybe the R version Ryan is using is very old?
cheers,
Paul
Erik Iverson wrote:
Ryan Kinzer wrote:
Erik
Thanks for helping. Both of them are factors.
That's the problem, they need to be of class Date. See the R NEWS
article about Date classes in Volume 4/1.
http://cran.r-project.org/doc/Rnews/
I don't see how they could be factors though, since you shouldn't be
able to subtract two factors from each other without a warning at least?
e.g., when I make up factors f1 and f2
>f1 - f2
<snip>
Warning message:
In Ops.factor(f1, f2) : - not meaningful for factors
We would have to have a small, reproducible example to know for sure
what's going on...
Best Regards,
Erik
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