check.options {grDevices}

R Documentation

Set Options with Consistency Checks

Description

Utility function for setting options with some consistency checks. The attributes of the new settings in new are checked for consistency with the model (often default) list in name.opt.

Usage

check.options(new, name.opt, reset = FALSE, assign.opt = FALSE,
              envir = .GlobalEnv,
              check.attributes = c("mode", "length"),
              override.check = FALSE)

Arguments

new	a named list
name.opt	character with the name of R object containing the default list.
reset	logical; if TRUE, reset the options from name.opt. If there is more than one R object with name name.opt, remove the first one in the search() path.
assign.opt	logical; if TRUE, assign the ...
envir	the environment used for get and assign.
check.attributes	character containing the attributes which check.options should check.
override.check	logical vector of length length(new) (or 1 which entails recycling). For those new[i] where override.check[i] == TRUE, the checks are overridden and the changes made anyway.

Value

A list of components with the same names as the one called name.opt. The values of the components are changed from the new list, as long as these pass the checks (when these are not overridden according to override.check).

Note

Option "names" is exempt from all the checks or warnings, as in the application it can be NULL or a variable-length character vector.

Author(s)

Martin Maechler

See Also

ps.options and pdf.options, which use check.options.

Examples

(L1 <- list(a=1:3, b=pi, ch="CH"))
check.options(list(a=0:2), name.opt = "L1")
check.options(NULL, reset = TRUE, name.opt = "L1")

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