R: Options Settings

options {base}

R Documentation

Options Settings

Description

options allows the user to set and examine a variety of global “options” which affect the way in which R computes and displays its results.

Usage

options(...)
.Options

Arguments

...

any options can be defined, using name = value. However, only the ones below are used in “base R”.

Further, options('name') == options()['name'], see the example.

prompt

a string, used for R's prompt; should usually end in a blank (" ").

continue

a string setting the prompt used for lines which continue over one line.

width

controls the number of characters on a line. You may want to change this if you resize the window that R is running in.

digits

controls the number of digits to print when printing numeric values. It is a suggestion only.

editor

sets the default text editor, e.g., for edit.

browser

default HTML browser used by help.start().

contrasts

the default contrasts used in model fitting such as with aov or lm.

expressions

sets a limit on the number of nested expressions that will be evaluated. This is especially important on the Macintosh since stack overflow is likely if this is set too high.

keep.source

When TRUE, the default, the source code for functions loaded by is stored in their "source" attribute, allowing comments to be kept in the right places. This does not apply to functions loaded by library.

na.action

the name of a function for treating missing values (NA's) for certain situations.

the (standalone) program used for displaying ASCII files on R's console. Defaults to ‘\$R\_HOME/bin/pager’.

papersize

the paper format used for graphics printing; currently read-only, set by environment variable R_PAPERSIZE, or in ‘config.site’.

printcmd

the command used for graphics printing; currently read-only, set by environment variable R_PRINTCMD, or in ‘config.site’.

show.signif.stars, show.coef.Pvalues

logical, affecting P value printing, see print.coefmat.

ts.eps

the relative tolerance for certain time series (ts) computations.

warn

sets the handling of warning messages. If warn is negative all warnings are ignored. If warn is zero (the default) warnings are stored until the top–level function returns. If fewer than 10 warnings were signalled they will be printed otherwise a message saying how many (max 50) were signalled. A top–level variable called last.warning is created and can be viewed through the function warnings. If warn is one, warnings are printed as they occur. If warn is two or larger all warnings are turned into errors.

error

an expression governing the handling of non-catastrophic errors such as those generated by stop as well as by signals and internally detected errors. The default expression is NULL: see stop for the behaviour in that case.

Details

Invoking options() with no arguments returns a list with the current values of the options. .Options is another way to access this list “read only”.

Accessing current options, usually will work with .Options$width (e.g.), rather than options("width") which is a list of length one.

Value

A list (in any case) with the previous values of the options changed, or all options when no arguments were given.

Examples

options() # printing all current options
op <- options(); str(op) # nicer printing

# .Options is the same:
all(sapply(1:length(op), function(i) all(.Options[[i]] == op[[i]])))

options('width')[[1]] == options()$width # the latter needs more memory
options(digits=20)
pi

# set the editor, and save previous value
old.o <- options(editor="nedit")
old.o

options(op)	# reset (all) initial options
options('digits')

## Not run: ## on error, terminate the R session with error status 66
options(error=quote(q("no", status=66, runLast=FALSE)))
stop("test it")

## End(Not run)

[Package base version 0.90 ]