| % File src/library/base/man/options.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2019 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{options} |
| \alias{options} |
| \alias{.Options} |
| \alias{getOption} |
| \alias{option} % so help files can do 'set \link{} \code{"foo"}' |
| |
| \alias{MC_CORES} |
| \alias{R_C_BOUNDS_CHECK} |
| \alias{R_DEFAULT_DEVICE} |
| \alias{R_KEEP_PKG_SOURCE} |
| \alias{R_INTERACTIVE_DEVICE} |
| |
| \title{Options Settings} |
| \description{ |
| Allow the user to set and examine a variety of global \emph{options} |
| which affect the way in which \R computes and displays its results. |
| } |
| \usage{ |
| options(\dots) |
| |
| getOption(x, default = NULL) |
| |
| .Options |
| } |
| %%-- NOTE : Keep the list up-to-date, |
| %%-- ==== Consider also the leading comments in ../../../main/options.c |
| \arguments{ |
| \item{\dots}{any options can be defined, using \code{name = value}. |
| However, only the ones below are used in base \R. |
| |
| Options can also be passed by giving a single unnamed argument which |
| is a named list. |
| } |
| \item{x}{a character string holding an option name.} |
| |
| \item{default}{if the specified option is not set in the options list, |
| this value is returned. This facilitates retrieving an option and |
| checking whether it is set and setting it separately if not.} |
| } |
| \details{ |
| Invoking \code{options()} with no arguments returns a list with the |
| current values of the options. Note that not all options listed below |
| are set initially. To access the value of a single option, one should |
| use, e.g., \code{getOption("width")} rather than |
| \code{options("width")} which is a \emph{list} of length one. |
| } |
| |
| \note{ |
| For compatibility with S there is a visible object \code{.Options} whose |
| value is a pairlist containing the current \code{options()} (in no |
| particular order). Assigning to it will make a local copy and not |
| change the original. (\emph{Using} it however is faster than calling |
| \code{options()}). |
| |
| An option set to \code{NULL} is indistinguishable from a non existing |
| option. |
| } |
| \value{ |
| For \code{getOption}, the current value set for option \code{x}, or |
| \code{default} (which defaults to \code{NULL}) if the option is unset. |
| |
| For \code{options()}, a list of all set options sorted by name. For |
| \code{options(name)}, a list of length one containing the set value, |
| or \code{NULL} if it is unset. For uses setting one or more options, |
| a list with the previous values of the options changed (returned |
| invisibly). |
| } |
| \section{Options used in base \R}{ |
| \describe{ |
| \item{\code{add.smooth}:}{typically logical, defaulting to |
| \code{TRUE}. Could also be set to an integer for specifying how |
| many (simulated) smooths should be added. This is currently only |
| used by \code{\link{plot.lm}}.} |
| |
| \item{\code{askYesNo}:}{a function (typically set by a front-end) |
| to ask the user binary response functions in a consistent way, |
| or a vector of strings used by \code{\link{askYesNo}} to use |
| as default responses for such questions.} |
| |
| \item{\code{browserNLdisabled}:}{logical: whether newline is |
| disabled as a synonym for \code{"n"} in the browser.} |
| |
| \item{\code{checkPackageLicense}:}{logical, not set by default. If |
| true, \code{\link{loadNamespace}} asks a user to accept any |
| non-standard license at first load of the package. |
| } |
| |
| \item{\code{check.bounds}:}{logical, defaulting to \code{FALSE}. If |
| true, a \link{warning} is produced whenever a |
| vector (atomic or \code{\link{list}}) is extended, by something |
| like \code{x <- 1:3; x[5] <- 6}.} |
| |
| \item{\code{CBoundsCheck}:}{logical, controlling whether |
| \code{\link{.C}} and \code{\link{.Fortran}} make copies to check for |
| array over-runs on the atomic vector arguments. |
| |
| Initially set from value of the environment variable |
| \env{R_C_BOUNDS_CHECK} (set to \code{yes} to enable).} |
| |
| \item{\code{conflicts.policy}:}{character string or list controlling |
| handling of conflicts found in calls to \code{\link{library}} or |
| \code{\link{require}}. See \code{\link{library}} for details.} |
| |
| \item{\code{continue}:}{a non-empty string setting the prompt used |
| for lines which continue over one line.} |
| |
| %% default is set in ../../profile/Common.R : |
| \item{\code{defaultPackages}:}{the packages that are attached by |
| default when \R starts up. Initially set from value of the |
| environment variable \env{R_DEFAULT_PACKAGES}, or if that is unset |
| to \code{c("datasets", "utils", "grDevices", "graphics", "stats", |
| "methods")}. (Set \env{R_DEFAULT_PACKAGES} to \code{NULL} or |
| a comma-separated list of package names.) It will not work to set |
| this in a \file{.Rprofile} file, as its value is consulted before |
| that file is read.} |
| |
| \item{\code{deparse.cutoff}:}{integer value controlling the |
| printing of language constructs which are \code{\link{deparse}}d. |
| Default \code{60}. |
| } |
| |
| \item{\code{deparse.max.lines}:}{controls the number of lines used |
| when deparsing in \code{\link{traceback}}, \code{\link{browser}}, |
| and upon entry to a function whose debugging flag is set. |
| Initially unset, and only used if set to a positive integer.} |
| |
| \item{\code{digits}:}{controls the number of \emph{significant} (see \code{\link{signif}}) digits to |
| print when printing numeric values. It is a suggestion only. |
| Valid values are 1\dots{}22 with default 7. See the note in |
| \code{\link{print.default}} about values greater than 15.} |
| |
| \item{\code{digits.secs}:}{controls the maximum number of digits to |
| print when formatting time values in seconds. Valid values |
| are 0\dots6 with default 0. See \code{\link{strftime}}.} |
| |
| \item{\code{download.file.extra}:}{Extra command-line argument(s) for |
| non-default methods: see \code{\link{download.file}}.} |
| |
| \item{\code{download.file.method}:}{Method to be used for |
| \code{download.file}. Currently download methods |
| \code{"internal"}, \code{"wininet"} (Windows only), |
| \code{"libcurl"}, \code{"wget"} and \code{"curl"} are available. |
| If not set, \code{method = "auto"} |
| is chosen: see \code{\link{download.file}}.} |
| |
| \item{\code{echo}:}{logical. Only used in non-interactive mode, |
| when it controls whether input is echoed. Command-line option |
| \option{--slave} sets this to \code{FALSE}, but otherwise |
| it starts the session as \code{TRUE}.} |
| |
| \item{\code{encoding}:}{The name of an encoding, default |
| \code{"native.enc"}. See \code{\link{connections}}.} |
| |
| \item{\code{error}:}{either a function or an expression governing |
| the handling of non-catastrophic errors such as those generated by |
| \code{\link{stop}} as well as by signals and internally detected |
| errors. If the option is a function, a call to that function, |
| with no arguments, is generated as the expression. By default |
| the option is not set: see \code{\link{stop}} for the behaviour in |
| that case. The functions \code{\link{dump.frames}} and |
| \code{\link{recover}} provide alternatives that allow post-mortem |
| debugging. Note that these need to specified as |
| e.g.\sspace{}\code{options(error = utils::recover)} in startup |
| files such as \file{\link{.Rprofile}}.} |
| |
| \item{\code{expressions}:}{sets a limit on the number of nested |
| expressions that will be evaluated. Valid values are |
| 25\dots500000 with default 5000. If you increase it, you may |
| also want to start \R with a larger protection stack; |
| see \option{--max-ppsize} in \code{\link{Memory}}. Note too that |
| you may cause a segfault from overflow of the C stack, and on OSes |
| where it is possible you may want to increase that. Once the |
| limit is reached an error is thrown. The current number under |
| evaluation can be found by calling \code{\link{Cstack_info}}.} |
| |
| \item{\code{interrupt}:}{a function taking no arguments to be called |
| on a user interrupt if the interrupt condition is not otherwise |
| handled.} |
| |
| \item{\code{keep.parse.data}:}{When internally storing source code |
| (\code{keep.source} is TRUE), also store parse data. Parse data can |
| then be retrieved with \code{\link{getParseData}()} and used e.g. for |
| spell checking of string constants or syntax highlighting. The value |
| has effect only when internally storing source code (see |
| \code{keep.source}). The default is \code{TRUE}.} |
| |
| \item{\code{keep.parse.data.pkgs}:}{As for \code{keep.parse.data}, used |
| only when packages are installed. Defaults to \code{FALSE} unless the |
| environment variable \env{R_KEEP_PKG_PARSE_DATA} is set to \code{yes}. |
| The space overhead of parse data can be substantial even after |
| compression and it causes performance overhead when loading packages.} |
| |
| \item{\code{keep.source}:}{When \code{TRUE}, the source code for |
| functions (newly defined or loaded) is stored internally |
| allowing comments to be kept in the right places. Retrieve the |
| source by printing or using \code{deparse(fn, control = |
| "useSource")}. |
| |
| The default is \code{\link{interactive}()}, i.e., \code{TRUE} for |
| interactive use.} |
| |
| %% used by tools::makeLazyLoading |
| \item{\code{keep.source.pkgs}:}{As for \code{keep.source}, used only |
| when packages are installed. Defaults to \code{FALSE} unless the |
| environment variable \env{R_KEEP_PKG_SOURCE} is set to \code{yes}.} |
| |
| \item{\code{matprod}:}{a string selecting the implementation of |
| the matrix products \code{\link{\%*\%}}, \code{\link{crossprod}}, and |
| \code{\link{tcrossprod}} for double and complex vectors: |
| \describe{ |
| \item{\code{"internal"}}{uses an unoptimized 3-loop algorithm |
| which correctly propagates \code{\link{NaN}} and |
| \code{\link{Inf}} values and is consistent in precision with |
| other summation algorithms inside \R like \code{\link{sum}} or |
| \code{\link{colSums}} (which now means that it uses a \code{long |
| double} accumulator for summation if available and enabled, |
| see \code{\link{capabilities}}).} |
| \item{\code{"default"}}{uses BLAS to speed up computation, but |
| to ensure correct propagation of \code{NaN} and \code{Inf} |
| values it uses an unoptimized 3-loop algorithm for inputs that may |
| contain \code{NaN} or \code{Inf} values. When deemed |
| beneficial for performance, \code{"default"} may call the |
| 3-loop algorithm unconditionally, i.e., without checking the |
| input for NaN/Inf values. The 3-loop algorithm uses (only) a |
| \code{double} accumulator for summation, which is consistent |
| with the reference BLAS implementation.} |
| \item{\code{"blas"}}{uses BLAS unconditionally without any |
| checks and should be used with extreme caution. BLAS |
| libraries do not propagate \code{\link{NaN}} or |
| \code{\link{Inf}} values correctly and for inputs with |
| \code{NaN}/\code{Inf} values the results may be undefined.} |
| \item{\code{"default.simd"}}{is experimental and will likely be |
| removed in future versions of \R. It provides the same behavior |
| as \code{"default"}, but the check whether the input contains |
| NaN/Inf values is faster on some SIMD hardware. On older |
| systems it will run correctly, but may be much slower than |
| \code{"default"}.} |
| } |
| } |
| |
| \item{\code{max.print}:}{integer, defaulting to \code{99999}. |
| \code{\link{print}} or \code{\link{show}} methods can make use of |
| this option, to limit the amount of information that is printed, |
| to something in the order of (and typically slightly less than) |
| \code{max.print} \emph{entries}.} |
| |
| \item{\code{OutDec}:}{character string containing a single |
| character. The preferred character to be used as the decimal |
| point in output conversions, that is in printing, plotting, |
| \code{\link{format}} and \code{\link{as.character}} but not when |
| deparsing nor by \code{\link{sprintf}} nor \code{\link{formatC}} |
| (which are sometimes used prior to printing.) |
| } |
| |
| \item{\code{pager}:}{the command used for displaying text files by |
| \code{\link{file.show}}, details depending on the platform: |
| \describe{ |
| \item{On a unix-alike}{defaults to \file{\var{\link{R_HOME}}/bin/pager}, which is a shell |
| script running the command-line specified by the environment |
| variable \env{PAGER} whose default is set at configuration, |
| usually to \command{less}.} |
| \item{On Windows}{defaults to \code{"internal"}, which uses a pager similar to the |
| GUI console. Another possibility is \code{"console"} to use the |
| console itself.} |
| } |
| Can be a character string or an \R function, in which case it |
| needs to accept the arguments \code{(files, header, |
| title, delete.file)} corresponding to the first four arguments of |
| \code{\link{file.show}}.} |
| |
| \item{\code{papersize}:}{the default paper format used by |
| \code{\link{postscript}}; set by environment variable |
| \env{R_PAPERSIZE} when \R is started: if that is unset or invalid |
| it defaults platform dependently |
| \describe{ |
| \item{on a unix-alike}{to a value derived from the locale category |
| \code{LC_PAPER}, or if that is unavailable to a default set |
| when \R was built.} |
| \item{on Windows}{to \code{"a4"}, or \code{"letter"} in US and |
| Canadian locales.} |
| }} |
| |
| \item{\code{PCRE_limit_recursion}:}{Logical: should |
| \code{\link{grep}(perl = TRUE)} and similar limit the maximal |
| recursion allowed when matching? PCRE can be built not to use a |
| recursion stack (see \code{\link{pcre_config}}, but it is by |
| default with a recursion limit of 10000000 which potentially needs |
| a very large C stack: see the discussion at |
| \url{http://www.pcre.org/original/doc/html/pcrestack.html}. If |
| true, the limit is reduced using \R's estimate of the C stack size |
| available (if known), otherwise 10000. If \code{NA}, the limit is |
| imposed only if any input string has 1000 or more bytes.} |
| |
| \item{\code{PCRE_study}:}{Logical or integer: should |
| \code{\link{grep}(perl = TRUE)} and similar \sQuote{study} the |
| patterns? Either logical or a numerical threshold for the minimum |
| number of strings to be matched for the pattern to be studied (the |
| default is \code{10})). Missing values and negative numbers are |
| treated as false.} |
| |
| \item{\code{PCRE_use_JIT}:}{Logical: should \code{\link{grep}(perl = |
| TRUE)}, \code{\link{strsplit}(perl = TRUE)} and similar make use |
| of PCRE's Just-In-Time compiler for studied patterns, if |
| available? Missing values are treated as false.} |
| |
| \item{\code{pdfviewer}:}{default PDF viewer. |
| The default is set from the environment variable \env{R_PDFVIEWER}, |
| the default value of which |
| \describe{ |
| \item{on a unix-alike}{is set when \R is configured, and} |
| \item{on Windows}{is the full path to \command{open.exe}, a utility |
| supplied with \R.} |
| }} |
| |
| \item{\code{printcmd}:}{the command used by \code{\link{postscript}} |
| for printing; set by environment variable \env{R_PRINTCMD} when |
| \R is started. This should be a command that expects either input |
| to be piped to \file{stdin} or to be given a single filename |
| argument. Usually set to \code{"lpr"} on a Unix-alike.} |
| |
| \item{\code{prompt}:}{a non-empty string to be used for \R's prompt; |
| should usually end in a blank (\code{" "}).} |
| |
| % verbatim, for checking " \t\n\"\\'`><=%;,|&{()}" |
| \item{\code{rl_word_breaks}:}{(Unix only:) Used for the readline-based terminal |
| interface. Default value \code{" \\t\\n\\"\\\\'`><=\%;,|&{()}"}.%" |
| |
| This is the set of characters use to break the input line into |
| tokens for object- and file-name completion. Those who do not use |
| spaces around operators may prefer\cr |
| \code{" \\t\\n\\"\\\\'`><=+-*\%;,|&{()}"}%" |
| } |
| |
| \item{\code{save.defaults}, \code{save.image.defaults}:}{ |
| see \code{\link{save}}.} |
| |
| \item{\code{scipen}:}{integer. A penalty to be applied |
| when deciding to print numeric values in fixed or exponential |
| notation. Positive values bias towards fixed and negative towards |
| scientific notation: fixed notation will be preferred unless it is |
| more than \code{scipen} digits wider.} |
| |
| \item{\code{setWidthOnResize}:}{a logical. If set and \code{TRUE}, \R |
| run in a terminal using a recent \code{readline} library will set |
| the \code{width} option when the terminal is resized.} |
| |
| \item{\code{showWarnCalls}, \code{showErrorCalls}:}{a logical. |
| Should warning and error messages show a summary of the call |
| stack? By default error calls are shown in non-interactive |
| sessions.} |
| |
| \item{\code{showNCalls}:}{integer. Controls how long the sequence |
| of calls must be (in bytes) before ellipses are used. Defaults to |
| 40 and should be at least 30 and no more than 500.} |
| |
| \item{\code{show.error.locations}:}{Should source locations of |
| errors be printed? If set to \code{TRUE} or \code{"top"}, the |
| source location that is highest on the stack (the most recent |
| call) will be printed. \code{"bottom"} will print the location |
| of the earliest call found on the stack. |
| |
| Integer values can select other entries. The value \code{0} |
| corresponds to \code{"top"} and positive values count down the |
| stack from there. The value \code{-1} corresponds to |
| \code{"bottom"} and negative values count up from there. |
| } |
| |
| \item{\code{show.error.messages}:}{a logical. Should error messages |
| be printed? Intended for use with \code{\link{try}} or a |
| user-installed error handler.} |
| |
| \item{\code{stringsAsFactors}:}{The default setting for arguments of |
| \code{\link{data.frame}} and \code{\link{read.table}}.} |
| |
| \item{\code{texi2dvi}:}{used by functions |
| \code{\link{texi2dvi}} and \code{\link{texi2pdf}} in package \pkg{tools}. |
| \describe{ |
| \item{unix-alike only:}{ |
| Set at startup from the environment variable \env{R_TEXI2DVICMD}, |
| which defaults first to the value of environment variable |
| \env{TEXI2DVI}, and then to a value set when \R was installed (the |
| full path to a \command{texi2dvi} script if one was found). If |
| necessary, that environment variable can be set to |
| \code{"emulation"}. |
| } } |
| } |
| |
| \item{\code{timeout}:}{integer. The timeout for some Internet |
| operations, in seconds. Default 60 seconds. See |
| \code{\link{download.file}} and \code{\link{connections}}.} |
| |
| \item{\code{topLevelEnvironment}:}{see \code{\link{topenv}} and |
| \code{\link{sys.source}}.} |
| |
| \item{\code{url.method}:}{character string: the default method for |
| \code{\link{url}}. Normally unset, which is equivalent to |
| \code{"default"}, which is \code{"internal"} except on Windows.} |
| |
| \item{\code{useFancyQuotes}:}{controls the use of |
| directional quotes in \code{\link{sQuote}}, \code{dQuote} and in |
| rendering text help (see \code{\link{Rd2txt}} in package |
| \pkg{tools}). Can be \code{TRUE}, \code{FALSE}, \code{"TeX"} or |
| \code{"UTF-8"}.} |
| |
| \item{\code{verbose}:}{logical. Should \R report extra information |
| on progress? Set to \code{TRUE} by the command-line option |
| \option{--verbose}.} |
| |
| \item{\code{warn}:}{sets the handling of warning messages. If |
| \code{warn} is negative all warnings are ignored. If \code{warn} |
| is zero (the default) warnings are stored until the top--level |
| function returns. If 10 or fewer warnings were signalled they |
| will be printed otherwise a message saying how many were |
| signalled. An object called \code{last.warning} is |
| created and can be printed through the function |
| \code{\link{warnings}}. If \code{warn} is one, warnings are |
| printed as they occur. If \code{warn} is two (or larger, coercible |
| to integer), all warnings are turned into errors.} |
| |
| \item{\code{warnPartialMatchArgs}:}{logical. If true, warns if |
| partial matching is used in argument matching.} |
| |
| \item{\code{warnPartialMatchAttr}:}{logical. If true, warns if |
| partial matching is used in extracting attributes via |
| \code{\link{attr}}.} |
| |
| \item{\code{warnPartialMatchDollar}:}{logical. If true, warns if |
| partial matching is used for extraction by \code{$}.} |
| |
| \item{\code{warning.expression}:}{an \R code expression to be called |
| if a warning is generated, replacing the standard message. If |
| non-null it is called irrespective of the value of option |
| \code{warn}.} |
| |
| \item{\code{warning.length}:}{sets the truncation limit for error |
| and warning messages. A non-negative integer, with allowed values |
| 100\dots8170, default 1000.} |
| |
| \item{\code{nwarnings}:}{the limit for the number of warnings kept |
| when \code{warn = 0}, default 50. This will discard messages if |
| called whilst they are being collected. If you increase this |
| limit, be aware that the current implementation pre-allocates |
| the equivalent of a named list for them, i.e., do not increase it to |
| more than say a million.} |
| |
| \item{\code{width}:}{controls the maximum number of columns on a |
| line used in printing vectors, matrices and arrays, and when |
| filling by \code{\link{cat}}. |
| |
| Columns are normally the same as characters except in East Asian |
| languages. |
| |
| You may want to change this if you re-size the window that \R is |
| running in. Valid values are 10\dots10000 with default normally |
| 80. (The limits on valid values are in file \file{Print.h} and can be |
| changed by re-compiling \R.) Some \R consoles automatically change |
| the value when they are resized. |
| |
| See the examples on \link{Startup} for one way to set this |
| automatically from the terminal width when \R is started. |
| } |
| } |
| |
| The \sQuote{factory-fresh} default settings of some of these options are |
| \tabular{ll}{ |
| \code{add.smooth} \tab \code{TRUE}\cr |
| \code{check.bounds} \tab \code{FALSE}\cr |
| \code{continue} \tab \code{"+ "}\cr |
| \code{digits} \tab \code{7}\cr |
| \code{echo} \tab \code{TRUE}\cr |
| \code{encoding} \tab \code{"native.enc"}\cr |
| \code{error} \tab \code{NULL}\cr |
| \code{expressions} \tab \code{5000}\cr |
| \code{keep.source} \tab \code{interactive()}\cr |
| \code{keep.source.pkgs} \tab \code{FALSE}\cr |
| \code{max.print} \tab \code{99999}\cr |
| \code{OutDec} \tab \code{"."}\cr |
| \code{prompt} \tab \code{"> "}\cr |
| \code{scipen} \tab \code{0} \cr |
| \code{show.error.messages} \tab \code{TRUE}\cr |
| \code{timeout} \tab \code{60}\cr |
| \code{verbose} \tab \code{FALSE}\cr |
| \code{warn} \tab \code{0}\cr |
| \code{warning.length} \tab \code{1000}\cr |
| \code{width} \tab \code{80}\cr |
| } |
| Others are set from environment variables or are platform-dependent. |
| } |
| \section{Options set in package grDevices}{ |
| These will be set when package \pkg{grDevices} (or its namespace) |
| is loaded if not already set. |
| \describe{ |
| \item{\code{bitmapType}:}{(Unix only, incl. macOS) character. The |
| default type for the |
| bitmap devices such as \code{\link{png}}. Defaults to |
| \code{"cairo"} on systems where that is available, or to |
| \code{"quartz"} on macOS where that is available.} |
| |
| \item{\code{device}:}{a character string giving |
| the name of a function, or the function object itself, |
| which when called creates a new graphics device of the default |
| type for that session. The value of this option defaults to the |
| normal screen device (e.g., \code{X11}, \code{windows} or |
| \code{quartz}) for an interactive session, and \code{pdf} |
| in batch use or if a screen is not available. If set to the name |
| of a device, the device is looked for first from the global |
| environment (that is down the usual search path) and then in the |
| \pkg{grDevices} namespace. |
| |
| The default values in interactive and non-interactive sessions are |
| configurable via environment variables |
| \env{R_INTERACTIVE_DEVICE} and \env{R_DEFAULT_DEVICE} |
| respectively. |
| |
| The search logic for \sQuote{the normal screen device} is that |
| this is \code{windows} on Windows, and \code{quartz} if available |
| on macOS (running at the console, and compiled into the build). |
| Otherwise \code{X11} is used if environment variable \env{DISPLAY} |
| is set. |
| } |
| |
| \item{\code{device.ask.default}:}{logical. The default for |
| \code{\link{devAskNewPage}("ask")} when a device is opened.} |
| |
| \item{\code{locatorBell}:}{logical. Should selection in \code{locator} |
| and \code{identify} be confirmed by a bell? Default \code{TRUE}. |
| Honoured at least on \code{X11} and \code{windows} devices.} |
| |
| \item{\code{windowsTimeout}:}{(Windows-only) integer vector of length 2 |
| representing two times in milliseconds. These control the |
| double-buffering of \code{\link{windows}} devices when that is |
| enabled: the first is the delay after plotting finishes |
| (default 100) and the second is the update interval during |
| continuous plotting (default 500). The values at the time the |
| device is opened are used.} |
| } |
| } |
| \section{Other options used by package graphics}{ |
| \describe{ |
| \item{\code{max.contour.segments}:}{positive integer, defaulting to |
| \code{25000} if not set. A limit on the number of |
| segments in a single contour line in \code{\link{contour}} or |
| \code{\link{contourLines}}.} |
| } |
| } |
| \section{Options set in package stats}{ |
| These will be set when package \pkg{stats} (or its namespace) |
| is loaded if not already set. |
| \describe{ |
| \item{\code{contrasts}:}{the default \code{\link{contrasts}} used in |
| model fitting such as with \code{\link{aov}} or \code{\link{lm}}. |
| A character vector of length two, the first giving the function to |
| be used with unordered factors and the second the function to be |
| used with ordered factors. By default the elements are named |
| \code{c("unordered", "ordered")}, but the names are unused.} |
| |
| \item{\code{na.action}:}{the name of a function for treating missing |
| values (\code{\link{NA}}'s) for certain situations, see |
| \code{\link{na.action}} and \code{\link{na.pass}}.} |
| |
| \item{\code{show.coef.Pvalues}:}{logical, affecting whether P |
| values are printed in summary tables of coefficients. See |
| \code{\link{printCoefmat}}.} |
| |
| \item{\code{show.nls.convergence}:}{logical, should \code{\link{nls}} |
| convergence messages be printed for successful fits?} |
| |
| \item{\code{show.signif.stars}:}{logical, should stars be printed on |
| summary tables of coefficients? See \code{\link{printCoefmat}}.} |
| |
| \item{\code{ts.eps}:}{the relative tolerance for certain time series |
| (\code{\link{ts}}) computations. Default \code{1e-05}.} |
| |
| \item{\code{ts.S.compat}:}{logical. Used to select S compatibility |
| for plotting time-series spectra. See the description of argument |
| \code{log} in \code{\link{plot.spec}}.} |
| } |
| } |
| \section{Options set (or used) in package utils}{ |
| These will be set (apart from \code{Ncpus}) when package \pkg{utils} |
| (or its namespace) is loaded if not already set. |
| \describe{ |
| \item{\code{BioC_mirror}:}{The URL of a Bioconductor mirror |
| for use by \code{\link{setRepositories}}, |
| e.g.\sspace{}the default \samp{"https://bioconductor.org"} |
| or the European mirror |
| \samp{"https://bioconductor.statistik.tu-dortmund.de"}. Can be set |
| by \code{\link{chooseBioCmirror}}.} |
| |
| \item{\code{browser}:}{The HTML browser to be used by |
| \code{\link{browseURL}}. This sets the default browser on UNIX or |
| a non-default browser on Windows. Alternatively, an \R function |
| that is called with a URL as its argument. See |
| \code{\link{browseURL}} for further details.} |
| |
| \item{\code{ccaddress}:}{default Cc: address used by |
| \code{\link{create.post}} (and hence\code{\link{bug.report}} and |
| \code{\link{help.request}}). Can be \code{FALSE} or \code{""}.} |
| |
| \item{\code{citation.bibtex.max}:}{default 1; the maximal number of |
| bibentries (\code{\link{bibentry}}) in a \code{\link{citation}} for |
| which the bibtex version is printed in addition to the text one.} |
| |
| \item{\code{de.cellwidth}:}{integer: the cell widths (number of |
| characters) to be used in the data editor \code{\link{dataentry}}. |
| If this is unset (the default), 0, negative or \code{NA}, variable |
| cell widths are used.} |
| |
| \item{\code{demo.ask}:}{default for the \code{ask} argument of |
| \code{\link{demo}}.} |
| |
| \item{\code{editor}:}{a non-empty character string or an \R function |
| that sets the default text editor, e.g., for \code{\link{edit}} |
| and \code{\link{file.edit}}. Set from the environment variable |
| \env{EDITOR} on UNIX, or if unset \env{VISUAL} or \command{vi}. |
| As a string it should specify the name of or path to an external |
| command.} |
| |
| \item{\code{example.ask}:}{default for the \code{ask} argument of |
| \code{\link{example}}.} |
| |
| \item{\code{help.ports}:}{optional integer vector for setting ports |
| of the internal HTTP server, see \code{\link{startDynamicHelp}}.} |
| |
| \item{\code{help.search.types}:}{default types of documentation |
| to be searched by \code{\link{help.search}} and \code{\link{??}}.} |
| |
| \item{\code{help.try.all.packages}:}{default for an argument of |
| \code{\link{help}}.} |
| |
| \item{\code{help_type}:}{default for an argument of |
| \code{\link{help}}, used also as the help type by \code{\link{?}}.} |
| |
| \item{\code{HTTPUserAgent}:}{string used as the \sQuote{user agent} in |
| HTTP(S) requests by \code{\link{download.file}}, \code{\link{url}} |
| and \code{\link{curlGetHeaders}}, or \code{NULL} when requests will |
| be made without a user agent header. The default is |
| \code{R (<version> <platform> <arch> <os>)} |
| except when \samp{libcurl} is used when it is |
| \code{libcurl/7.<xx>.<y>} for the \samp{libcurl} version in use.} |
| |
| \item{\code{install.lock}:}{logical: should per-directory package |
| locking be used by \code{\link{install.packages}}? Most useful |
| for binary installs on macOS and Windows, but can be used in a |
| startup file for source installs \emph{via} |
| \command{R CMD \link{INSTALL}}. For binary installs, can also be |
| the character string \code{"pkglock"}.} |
| |
| \item{\code{internet.info}:}{The minimum level of information to be |
| printed on URL downloads etc, using the \code{"internal"} and |
| \code{"libcurl"} methods. |
| Default is 2, for failure causes. Set to 1 or 0 to get more |
| detailed information (for the \code{"internal"} method 0 provides |
| more information than 1). |
| } |
| |
| \item{\code{install.packages.check.source}:}{Used by |
| \code{\link{install.packages}} (and indirectly |
| \code{\link{update.packages}}) on platforms which support binary |
| packages. Possible values \code{"yes"} and \code{"no"}, with |
| unset being equivalent to \code{"yes"}.} |
| |
| \item{\code{install.packages.compile.from.source}:}{Used by |
| \code{\link{install.packages}(type = "both")} (and indirectly |
| \code{\link{update.packages}}) on platforms which |
| support binary packages. Possible values are \code{"never"}, |
| \code{"interactive"} (which means ask in interactive use and |
| \code{"never"} in batch use) and \code{"always"}. The default is |
| taken from environment variable |
| \env{R_COMPILE_AND_INSTALL_PACKAGES}, with default |
| \code{"interactive"} if unset. However, \code{install.packages} |
| uses \code{"never"} unless a \command{make} program is found, |
| consulting the environment variable \env{MAKE}.} |
| |
| \item{\code{mailer}:}{default emailing method used by |
| \code{\link{create.post}} and hence \code{\link{bug.report}} and |
| \code{\link{help.request}}.} |
| |
| \item{\code{menu.graphics}:}{Logical: should graphical menus be used |
| if available?. Defaults to \code{TRUE}. Currently applies to |
| \code{\link{select.list}}, \code{\link{chooseCRANmirror}}, |
| \code{\link{setRepositories}} and to select from multiple (text) |
| help files in \code{\link{help}}.} |
| |
| \item{\code{Ncpus}:}{an integer \eqn{n \ge 1}{n >= 1}, used in |
| \code{\link{install.packages}} as default for the number of cpus |
| to use in a potentially parallel installation, as |
| \code{Ncpus = getOption("Ncpus", 1L)}, i.e., when unset is |
| equivalent to a setting of 1.} |
| |
| \item{\code{pkgType}:}{The default type of packages to be downloaded |
| and installed -- see \code{\link{install.packages}}. |
| Possible values are platform dependently |
| \describe{ |
| \item{on Windows}{ |
| \code{"win.binary"}, \code{"source"} and |
| \code{"both"} (the default).} |
| \item{on unix-alikes}{\code{"source"} (the default except under a |
| CRAN macOS build), \code{"mac.binary.el-capitan"} and |
| \code{"both"} (the default for CRAN macOS builds). |
| (\code{"mac.binary.mavericks"}, \code{"mac.binary.leopard"}, |
| \code{"mac.binary.universal"} are no longer in use.)} |
| } |
| Value \code{"binary"} is a synonym for the native binary type (if |
| there is one); \code{"both"} is used by |
| \code{\link{install.packages}} to choose between source and binary |
| installs. |
| } |
| |
| \item{\code{repos}:}{URLs of the repositories for use by |
| \code{\link{update.packages}}. Defaults to |
| \code{c(CRAN="@CRAN@")}, a value that causes some utilities to |
| prompt for a CRAN mirror. To avoid this do set the CRAN mirror, |
| by something like |
| \code{local({r <- getOption("repos"); r["CRAN"] <- "http://my.local.cran"; |
| options(repos = r)})}. |
| |
| Note that you can add more repositories (Bioconductor, |
| R-Forge, Rforge.net \dots) |
| using \code{\link{setRepositories}}. |
| } |
| \item{\code{SweaveHooks}, \code{SweaveSyntax}:}{ |
| see \code{\link{Sweave}}. |
| } |
| |
| \item{\code{unzip}:}{a character string used by \code{\link{unzip}}: |
| the path of the external program \command{unzip} or \code{"internal"}. |
| Defaults (platform dependently) |
| \describe{ |
| \item{on unix-alikes}{to the value of \env{R_UNZIPCMD}, which is set in |
| \file{etc/Renviron} to the path of the \code{unzip} command found |
| during configuration and otherwise to \code{""}.} |
| \item{on Windows}{to \code{"internal"} when the internal unzip |
| code is used.} |
| } |
| } |
| |
| } |
| } |
| \section{Options set in package parallel}{ |
| These will be set when package \pkg{parallel} (or its namespace) |
| is loaded if not already set. |
| \describe{ |
| \item{\code{mc.cores}:}{a integer giving the maximum allowed number |
| of \emph{additional} \R processes allowed to be run in parallel to |
| the current \R process. Defaults to the setting of the |
| environment variable \env{MC_CORES} if set. Most applications |
| which use this assume a limit of \code{2} if it is unset. |
| } |
| } |
| } |
| \section{Options used on Unix only}{ |
| \describe{ |
| \item{\code{dvipscmd}:}{character string giving a command to be used in |
| the (deprecated) off-line printing of help pages \emph{via} |
| PostScript. Defaults to \command{"dvips"}.} |
| } |
| } |
| \section{Options used on Windows only}{ |
| \describe{ |
| \item{\code{warn.FPU}:}{logical, by default undefined. If true, |
| a \link{warning} is produced whenever \link{dyn.load} repairs the |
| control word damaged by a buggy DLL.} |
| } |
| } |
| |
| \references{ |
| Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) |
| \emph{The New S Language}. |
| Wadsworth & Brooks/Cole. |
| } |
| \examples{ |
| op <- options(); utils::str(op) # op is a named list |
| |
| getOption("width") == options()$width # the latter needs more memory |
| options(digits = 15) |
| pi |
| |
| # set the editor, and save previous value |
| old.o <- options(editor = "nedit") |
| old.o |
| |
| options(check.bounds = TRUE, warn = 1) |
| x <- NULL; x[4] <- "yes" # gives a warning |
| |
| options(digits = 5) |
| print(1e5) |
| options(scipen = 3); print(1e5) |
| |
| options(op) # reset (all) initial options |
| options("digits") |
| |
| \dontrun{## set contrast handling to be like S |
| options(contrasts = c("contr.helmert", "contr.poly")) |
| } |
| |
| \dontrun{## on error, terminate the R session with error status 66 |
| options(error = quote(q("no", status = 66, runLast = FALSE))) |
| stop("test it") |
| } |
| |
| \dontrun{## Set error actions for debugging: |
| ## enter browser on error, see ?recover: |
| options(error = recover) |
| ## allows to call debugger() afterwards, see ?debugger: |
| options(error = dump.frames) |
| ## A possible setting for non-interactive sessions |
| options(error = quote({dump.frames(to.file = TRUE); q()})) |
| } |
| |
| # Compare the two ways to get an option and use it |
| # acconting for the possibility it might not be set. |
| if(as.logical(getOption("performCleanp", TRUE))) |
| cat("do cleanup\n") |
| |
| \dontrun{ |
| # a clumsier way of expressing the above w/o the default. |
| tmp <- getOption("performCleanup") |
| if(is.null(tmp)) |
| tmp <- TRUE |
| if(tmp) |
| cat("do cleanup\n") |
| } |
| |
| } |
| \keyword{environment} |
| \keyword{error} |
| \keyword{print} |