

   PPlloott AAnnnnoottaattiioonn

        title(main = "", sub = "", xlab = "", ylab = "", ...)

   AArrgguummeennttss::

       main: The main title (on top) using font and size (char-
             acter expansion) `par("font.main")' and color
             `par("col.main")'.

        sub: Sub-title (at bottom) using font and size
             `par("font.sub")' and color `par("col.sub")'.

       xlab: X axis label using font and character expansion
             `par("font.axis")' and color `par("col.axis")'.

       ylab: Y axis label, same font attributes as `xlab'.

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

   DDeessccrriippttiioonn::

        This function can be used to add labels to a plot.  Its
        first four principal arguments can also be used as
        arguments in most high-level plotting functions.  They
        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.

   SSeeee AAllssoo::

        `mtext', `text'.

   EExxaammpplleess::

        plot(cars, main = "")
        title(main = "Stopping Distance versus Speed")

        x <- seq(-4, 4, len = 101)
        y <- cbind(sin(x), cos(x))
        matplot(x, y, type = "l", xaxt = "n",
                main = expression(paste(plain(sin) * phi, "  and  ",
                                        plain(cos) * phi)),
             ylab = expression("sin" * phi, "cos" * phi),    # only 1st is taken
             xlab = expression(paste("Phase Angle ", phi)),
             col.main = "blue")
        axis(1, at = c(-pi, -pi/2, 0, pi/2, pi),
             lab = expression(-pi, -pi/2, 0, pi/2, pi))
        abline(h = 0, v = pi/2 * c(-1,1), lty = 2, lwd = .1, col = "gray70")

        plot(cars, main = "")
        title(main = "Stopping Distance versus Speed")

        x <- seq(-4, 4, len = 101)
        y <- cbind(sin(x), cos(x))
        matplot(x, y, type = "l", xaxt = "n",
                main = expression(paste(plain(sin) * phi, "  and  ",
                                        plain(cos) * phi)),
             ylab = expression("sin" * phi, "cos" * phi),    # only 1st is taken
             xlab = expression(paste("Phase Angle ", phi)),
             col.main = "blue")
        axis(1, at = c(-pi, -pi/2, 0, pi/2, pi),
             lab = expression(-pi, -pi/2, 0, pi/2, pi))
        abline(h = 0, v = pi/2 * c(-1,1), lty = 2, lwd = .1, col = "gray70")

