| callArg {playwith} | R Documentation |
Part of the playwith Application Programming Interface.
callArg(playState, arg, name = NULL) callArg(playState, arg, name = NULL) <- value
playState |
a playState object representing the plot, window and device. |
arg |
the argument name or number in the plot call (playState$call).
Argument numbers start from 1 (so 0 refers to the function name).
For setting, this can also be an expression
|
name |
the argument name given as a character string.
This is sometimes a convenient alternative to the quoted arg. |
value |
the value to set for argument arg. |
These functions get and set argument values in the playState plot call.
While it would be easy to get and set arguments in playState$call directly,
these API functions help by:
playState$env).
exact=TRUE (see [[).
returns the value of the specified argument,
as if using the $ or [[ extractor functions, but
evaluated in a local environment (playState$env).
Felix Andrews felix@nfrac.org
if (interactive()) {
library(lattice)
playwith(xyplot(1:10 ~ 1:10))
playState <- playDevCur()
callArg(playState, pch) # NULL
callArg(playState, pch) <- "$"
playReplot(playState)
callArg(playState, pch) # "$"
callArg(playState, name="pch") # "$"
callArg(playState, scales$x$cex) <- 2
playReplot(playState)
}