

options {base}                               R Documentation

_O_p_t_i_o_n_s _S_e_t_t_i_n_g_s

_D_e_s_c_r_i_p_t_i_o_n_:

     `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.

_U_s_a_g_e_:

     options(...)
     .Options

_A_r_g_u_m_e_n_t_s_:

     ...: 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 print-
          ing 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 expres-
          sions 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 val-
          ues (`NA''s) for certain situations.

   pager: 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; cur-
          rently 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_PRINT-
          CMD', 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 oth-
          erwise 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-catas-
          trophic 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.

_D_e_t_a_i_l_s_:

     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.

_V_a_l_u_e_:

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

_E_x_a_m_p_l_e_s_:

     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')

     ## on error, terminate the R session with error status 66
     options(error=quote(q("no", status=66, runLast=FALSE)))
     stop("test it")

