[R] Combining factors

[Peter Dalgaard]

Rainer M Krug <RKrug at sun.ac.za> writes:

> Hi
> 
> I know this is a basic question and I know I have done it before but I 
> can't find the answer any more.
> 
> I have a data set, say:
> 
> F1, F2, Value
> 
> F1 and F2 are Factors.
> 
> I would like to plot
> 
> plot(TheCombinationOf(F1, F2), Value)
> 
> I remember there was a function for TheCombinationOf() but I don't 
> remember the name.
> 
> I could create a new factor based on F1 and F2, but I would prefer the 
> other soluytion.
> 
> Any help welcome,

F1:F2
interaction(F1,F2)

There are some differences so lookup the help page for the latter.

-- 
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