M.Kondrin wrote:
Why this command does not return grob? What is special about grill and what makes it different from axis, lines, rectangles...
Most of the predefined grid drawing functions do two things: draw something and create and (invisibly) return a grob (graphical object). This means that they can be used in several different ways: "procedurally" just for their side effect (drawing something); or "functionally" for the object they produce (e.g., to use in the placement or sizing of another object); or both (e.g., to have a record of what has been drawn that can be uniquely identified and edited). The default behaviour is "both" so that grid functions appear to work like their standard graphics counterparts (i.e., they just draw something).
Functions that call the grid drawing functions can choose to just draw something, or they can choose to use the graphical objects from the grid functions to produce a graphical object of their own. Ideally, a new function will do the latter so that functions that want to call it also have a choice. But it is easier to write a function that just does drawing.
grid.grill is an example of a function that just does drawing. It's a convenience function that was easy to write. It should be rewritten to produce a graphical object at some stage -- perhaps a good exercise for someone learning grid? :)
Paul -- Dr Paul Murrell Department of Statistics The University of Auckland Private Bag 92019 Auckland New Zealand 64 9 3737599 x85392 [EMAIL PROTECTED]
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