[R] Conditioning variables in lattice - not all combinations
Deepayan Sarkar
deepayan.sarkar at gmail.com
Sun Oct 5 22:09:08 CEST 2008
On 10/5/08, Saptarshi Guha <saptarshi.guha at gmail.com> wrote:
> Hello,
> I have a shingle A and B. A has 5 levels and B has 4 levels.
> Also, I have 8
> levels of a factor C. I wish to xyplot( x ~ y | C *A *B,data=data),
>
> I think this is how the lattice conditioning works:
> If i'm not mistaken, all possible combinations of C,A,B
> , a subset of the data is accordingly taken and x~y is plotted.
> However, I
> have empty sets for some levels and these are plotted as empty panels.
> (e.g for A=1, there are only 2 levels of B).
>
> (I saw the solution A:B on the mailing list, which does not work in my
> case, since I'd like the multi-level strip titles.)
With some simple string manipulation, you should be able to write a
strip function that reproduces multi-level annotation even with
interactions.
> Is there a way to solve this?
No. Your situation is analogous to a matrix (or array) with NA
entries. You cannot omit NA cells without omitting entire rows or
columns (margins). On the other hand, you can convert the array into a
vector (analogous to conditioning on A:B:C) and then omit individual
NA cells.
-Deepayan
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