text                  package:base                  R Documentation

_A_d_d _T_e_x_t _t_o _a _P_l_o_t

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

     `text' draws the strings given in the vector `labels' at the
     coordinates given by `x' and `y'. `y' may be missing since
     `xy.coords(x,y)' is used for construction of the coordinates.

_U_s_a_g_e:

     text (x, ...)
     text.default (x, y = NULL, labels = seq(along = x), adj = NULL,
            pos = NULL, offset = 0.5, vfont = NULL,
            cex = 1, col = NULL, font = NULL, xpd = NULL, ...)

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

    x, y: numeric vectors of coordinates where the text `labels' should
          be written.  If the length of `x' and `y' differs, the
          shorter one is recycled.

  labels: one or more character strings or expressions specifying the
          text to be written.

     adj: one or two values in [0,1] which specify the x (and
          optionally y) adjustment of the labels.

     pos: a position specifier for the text.  If specified this
          overrides any `adj' value given.  Values of `1', `2', `3' and
          `4', respectively indicate positions below, to the left of,
          above and to the right of the specified coordinates.

  offset: when `pos' is specified, this value gives the offset of the
          label from the specified coordinate in fractions of a
          character width.

   vfont: if a character vector of length 2 is specified, then Hershey
          vector fonts are used.  The first element of the vector
          selects a typeface and the second element selects a style.

     cex: numeric character expansion factor; multiplied by
          `par("cex")' yields the final character size.

col, font: the color and font to be used; these default to the values
          of the global graphical parameters in `par()'.

     xpd: (where) should clipping take place?  Defaults to
          `par("xpd")'.

     ...: further graphical parameters (from `par').

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

     `labels' must be of type `character' or `expression'.  In the
     latter case, quite a bit of mathematical notation is available
     such as sub- and superscripts, greek letters, fractions, etc.

     `adj' allows adjustment of the text with respect to `(x,y)'.
     Values of 0, 0.5, and 1 specify left/bottom, middle and right/top,
     respectively.  The default is for centered text, i.e., `adj =
     c(0.5, 0.5)'. Accurate vertical centering needs character metric
     information on individual characters, which is only available on
     some devices.

     The `pos' and `offset' arguments can be used in conjunction with
     values returned by `identify' to recreate an interactively
     labelled plot.

     Text can be rotated by using graphical parameters `srt' (see
     `par'); this rotates about the centre set by `adj'.

     Graphical parameters `col', `cex' and `font' can be vectors and
     will then be applied cyclically to the `labels' (and extra values
     will be ignored).

_S_e_e _A_l_s_o:

     `mtext', `title', `Hershey' for details on Hershey vector fonts,
     `plotmath' for details and more examples on mathematical
     annotation.

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

     plot(-1:1,-1:1, type = "n", xlab = "Re", ylab = "Im")
     K <- 16; text(exp(1i * 2 * pi * (1:K) / K), col = 2)

     ## The following two examples use latin1 characters: these may not
     ## appear correctly (or be omitted entirely).
     plot(1:10, 1:10, main = "text(..) examples\n~~~~~~~~~~~~~~",
          sub = "R is GNU , but not  ..")
     mtext("ISO-accents:    < <", side=3)
     points(c(6,2), c(2,1), pch = 3, cex = 4, col = "red")
     text(6, 2, "the text is CENTERED around (x,y) = (6,2) by default",
          cex = .8)
     text(2, 1, "or Left/Bottom - JUSTIFIED at (2,1) by `adj = c(0,0)'",
          adj = c(0,0))
     text(4, 9, expression(hat(beta) == (X^t * X)^{-1} * X^t * y))
     text(4, 8.4, "expression(hat(beta) == (X^t * X)^{-1} * X^t * y)", cex = .75)
     text(4, 7, expression(bar(x) == sum(frac(x[i], n), i==1, n)))

     ## Two more latin1 examples
     text(5,10.2,"Le franais, c'est faile: Rgles, Libert, Egalit, Fraternit..")
     text(5,9.8, "Jetz no chli zrittsch: (noch ein bichen Zrcher deutsch)")

