R: Accessing Auxiliary Information During Plotting

G_panel.number {lattice}

R Documentation

Accessing Auxiliary Information During Plotting

Description

Control over lattice plots are provided through a collection of user specifiable functions that perform various tasks during the plotting. Not all information is available to all functions. The functions documented here attempt to provide a consistent interface to access relevant information from within these user specified functions, namely those specified as the panel, strip and axis functions. Note that this information is not available to the prepanel function, which is executed prior to the actual plotting.

Usage


current.row(prefix)
current.column(prefix)
panel.number(prefix)
packet.number(prefix)
which.packet(prefix)

trellis.currentLayout(which = c("packet", "panel"), prefix)

Arguments

`which`	whether return value (a matrix) should contain panel numbers or packet numbers, which are usually, but not necessarily, the same (see below for details).
`prefix`	A character string acting as a prefix identifying the plot of a `"trellis"` object. Only relevant when a particular page is occupied by more than one plot. Defaults to the value appropriate for the last `"trellis"` object printed. See `trellis.focus`.

Value

trellis.currentLayout returns a matrix with as many rows and columns as in the layout of panels in the current plot. Entries in the matrix are integer indices indicating which packet (or panel; see below) occupies that position, with 0 indicating the absence of a panel. current.row and current.column return integer indices specifying which row and column in the layout are currently active. panel.number returns an integer counting which panel is being drawn (starting from 1 for the first panel, a.k.a. the panel order). packet.number gives the packet number according to the packet order, which is determined by varying the first conditioning variable the fastest, then the second, and so on. which.packet returns the combination of levels of the conditioning variables in the form of a numeric vector as long as the number of conditioning variables, with each element an integer indexing the levels of the corresponding variable.

Note

The availability of these functions make redundant some features available in earlier versions of lattice, namely optional arguments called panel.number and packet.number that were made available to panel and strip. If you have written such functions, it should be enough to replace instances of panel.number and packet.number by the corresponding function calls. You should also remove panel.number and packet.number from the argument list of your function to avoid a warning.

If these accessor functions are not enough for your needs, feel free to contact the maintainer and ask for more.

Author(s)

Deepayan Sarkar Deepayan.Sarkar@R-project.org