R: Set Options with Consistency Checks

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

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")

[Package grDevices version 3.4.1 Index]