text            package:graphics            R Documentation(latin1)

_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, ...)

     ## Default S3 method:
     text (x, y = NULL, labels = seq_along(x), adj = NULL,
          pos = NULL, offset = 0.5, vfont = NULL,
          cex = 1, col = NULL, font = 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: a character vector or expression specifying the _text_ to be
          written.  An attempt is made to coerce other language objects
          (names and calls) to expressions, and vectors and other
          classed objects to character vectors by 'as.character'. If
          'labels' is longer than 'x' and 'y', the coordinates are
          recycled to the length of 'labels'.

     adj: one or two values in [0,1] which specify the x (and
          optionally y) adjustment of the labels.  On most devices
          values outside that interval will also work.

     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: 'NULL' for the current font family, or a character vector of
          length 2 for Hershey vector fonts.  The first element of the
          vector selects a typeface and the second element selects a
          style.  Ignored if 'labels' is an expression.

     cex: numeric *c*haracter *ex*pansion factor; multiplied by
          'par("cex")' yields the final character size. 'NULL' and 'NA'
          are equivalent to '1.0'.

col, font: the color and (if 'vfont = NULL') font to be used, possibly
          vectors. These default to the values of the global graphical
          parameters in 'par()'.

     ...: further graphical parameters (from 'par'), such as 'srt',
          'family' and 'xpd'.

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

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

     'adj' allows _adj_ustment of the text with respect to '(x,y)'.
     Values of 0, 0.5, and 1 specify left/bottom, middle and right/top
     alignment, 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.  Vertical alignment is done slightly
     differently for character strings and for expressions:
     'adj=c(0,0)' means to left-justify and to align on the baseline
     for strings but on the bottom of the bounding box for expressions.
     This also affects vertical centering: for strings the centering
     excludes any descenders whereas for expressions it includes them.

     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).  'NA' values of 'font' are replaced by
     'par("font")'.

     Labels whose 'x', 'y', 'labels', 'cex' or 'col' value is 'NA' are
     omitted from the plot.

     What happens when 'font = 5' (the symbol font) is selected can be
     both device- and locale-dependent.  Most often 'labels' will be
     interpreted in the Adobe symbol encoding, so e.g. '"d"' is delta,
     and '"\300"' is aleph.

_E_u_r_o _s_y_m_b_o_l:

     The Euro symbol was introduced relatively recently and may not be
     available in older fonts.  In recent versions of Adobe symbol
     fonts it is character 160, so 'text(x, y, "\xA0", font = 5)' may
     work. People using Western European locales on Unix-alikes can
     probably select ISO-8895-15 (Latin-9) which has the Euro as
     character 165: this can also be used for 'postscript' and 'pdf'.
     It is '\u20ac' in Unicode, which can be used in UTF-8 locales.

     The Euro should be rendered correctly by 'X11' in UTF-8 locales,
     but the corresponding single-byte encoding in 'postscript' and
     'pdf' will need to be selected as 'ISOLatin9.enc'.

_R_e_f_e_r_e_n_c_e_s:

     Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) _The New S
     Language_. Wadsworth & Brooks/Cole.

     Murrell, P. (2005) _R Graphics_. Chapman & Hall/CRC Press.

_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("Latin-1 accented chars:   < <", 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)")

