[R] How to write a new "top-level" Trellis/lattice function?

[Deepayan Sarkar]

On Tuesday 01 February 2005 07:53, Marc Paterno wrote:
> Hello,
>
> I am trying to write a new "top level" Trellis/lattice function.
> By "top-level", I mean a function like 'xyplot', 'histogram',
> 'bwplot', etc.
> These functions all call 'trellis.skeleton', which I am unable to
> call;
> an attempt to invoke the function that does so yields the error
> message:
>
> -----
> Error in do.call("trellis.skeleton", c(list(cond = cond, aspect =
> aspect,  :
>         couldn't find function "trellis.skeleton"
> -----
> 
> It seems that 'trellis.skeleton' is an internal (to lattice)
> function. Is this correct, and if so, what is the recommended way to
> develop a new
> top-level Trellis/lattice function?

What do you need to do that cannot be done by writing special panel and 
prepanel functions? See for example, the definition of dotplot, or 
xYplot in package Hmisc.

The only reason to have a new top-level function I can think of is if 
you need a fundametally different form of the formula. If that's the 
case, can you give us more details?

Deepayan