grid.text                package:grid                R Documentation

Draw Text

Description:

     These functions create and draw text and plotmath expressions.

Usage:

     grid.text(label, x = unit(0.5, "npc"), y = unit(0.5, "npc"), 
               just = "centre", hjust = NULL, vjust = NULL, rot = 0,
               check.overlap = FALSE, default.units = "npc",
               name = NULL, gp = gpar(), draw = TRUE, vp = NULL)

     textGrob(label, x = unit(0.5, "npc"), y = unit(0.5, "npc"), 
               just = "centre", hjust = NULL, vjust = NULL, rot = 0,
               check.overlap = FALSE, default.units = "npc",
               name = NULL, gp = gpar(), vp = NULL)

Arguments:

   label: A character or expression vector.  Other objects are coerced
          by 'as.graphicsAnnot'.

       x: A numeric vector or unit object specifying x-values.

       y: A numeric vector or unit object specifying y-values.

    just: The justification of the text  relative to its (x, y)
          location.  If there are two values, the first value specifies
          horizontal justification and the second value specifies
          vertical justification.  Possible string values are:
          '"left"', '"right"', '"centre"', '"center"', '"bottom"', and
          '"top"'.  For numeric values, 0 means left alignment and 1
          means right alignment. 

   hjust: A numeric vector specifying horizontal justification. If
          specified, overrides the 'just' setting.

   vjust: A numeric vector specifying vertical justification. If
          specified, overrides the 'just' setting.

     rot: The angle to rotate the text.

check.overlap: A logical value to indicate whether to check for and
          omit overlapping text.

default.units: A string indicating the default units to use if 'x' or
          'y' are only given as numeric vectors.

    name: A character identifier. 

      gp: An object of class 'gpar', typically the output from a call
          to the function 'gpar'.  This is basically a list of
          graphical parameter settings.

    draw: A logical value indicating whether graphics output should be
          produced.

      vp: A Grid viewport object (or NULL).

Details:

     Both functions create a text grob (a graphical object describing
     text), but only 'grid.text' draws the text (and then only if
     'draw' is 'TRUE').

     If the 'label' argument is an expression, the output is formatted
     as a mathematical annotation, as for base graphics text.

Value:

     A text grob.  'grid.text' returns the value invisibly.

Author(s):

     Paul Murrell

See Also:

     Grid, 'viewport'

Examples:

     grid.newpage()
     x <- stats::runif(20)
     y <- stats::runif(20)
     rot <- stats::runif(20, 0, 360)
     grid.text("SOMETHING NICE AND BIG", x=x, y=y, rot=rot,
               gp=gpar(fontsize=20, col="grey"))
     grid.text("SOMETHING NICE AND BIG", x=x, y=y, rot=rot,
               gp=gpar(fontsize=20), check=TRUE)
     grid.newpage()
     draw.text <- function(just, i, j) {
       grid.text("ABCD", x=x[j], y=y[i], just=just)
       grid.text(deparse(substitute(just)), x=x[j], y=y[i] + unit(2, "lines"),
                 gp=gpar(col="grey", fontsize=8))
     }
     x <- unit(1:4/5, "npc")
     y <- unit(1:4/5, "npc")
     grid.grill(h=y, v=x, gp=gpar(col="grey"))
     draw.text(c("bottom"), 1, 1)
     draw.text(c("left", "bottom"), 2, 1)
     draw.text(c("right", "bottom"), 3, 1)
     draw.text(c("centre", "bottom"), 4, 1)
     draw.text(c("centre"), 1, 2)
     draw.text(c("left", "centre"), 2, 2)
     draw.text(c("right", "centre"), 3, 2)
     draw.text(c("centre", "centre"), 4, 2)
     draw.text(c("top"), 1, 3)
     draw.text(c("left", "top"), 2, 3)
     draw.text(c("right", "top"), 3, 3)
     draw.text(c("centre", "top"), 4, 3)
     draw.text(c(), 1, 4)
     draw.text(c("left"), 2, 4)
     draw.text(c("right"), 3, 4)
     draw.text(c("centre"), 4, 4)

