R: The Default Scatterplot Function

plot.default {base}

R Documentation

The Default Scatterplot Function

Description

Draw a scatter plot with “decorations” such as axes and titles in the active graphics window.

Usage

plot.default(x, y = NULL, type = "p",  xlim = NULL, ylim = NULL,
             log = "", main = NULL, sub = NULL, xlab = NULL, ylab = NULL,
             ann = par("ann"), axes = TRUE, frame.plot = axes,
             panel.first = NULL, panel.last = NULL,
             col = par("fg"), bg = NA, pch = par("pch"),
             cex = par("cex"), lty = par("lty"), lwd = par("lwd"),
             asp = NA, ...)

Arguments

x, y

the x and y arguments provide the x and y coordinates for the plot. Any reasonable way of defining the coordinates is acceptable. See the function xy.coords for details.

type

the type of plot desired. The following possibilities are possible; "p" for points, "l" for lines, "o" for overplotted points and lines, "b" or c for points joined by lines, "s" and "S" for step functions and "h" for high density vertical lines.

xlim

the x limits (min,max) of the plot.

ylim

the y limits of the plot.

log

a character string which contains "x" if the x axis is to be logarithmic, "y" if the y axis is to be logarithmic and "xy" or "yx" if both axes are to be logarithmic.

main

a main title for the plot.

sub

a sub title for the plot.

xlab

a label for the x axis.

ylab

a label for the y axis.

ann

a logical value indicating whether the default annotation (title and x and y axis labels) should appear on the plot.

axes

a logical value indicating whether axes should be drawn on the plot.

frame.plot

a logical indicating whether a box should be drawn around the plot.

panel.first

an expression to be evaluated after the plot axes are set up but before any plotting takes place. This can be useful for drawing background grids or scatterplot smooths.

panel.last

an expression to be evaluated after plotting has taken place.

col

The colors for lines and points. Multiple colors can be specified so that each point can be given its own color. If there are fewer colors than points they are recycled in the standard fashion.

bg

background color of ???

pch

a vector of plotting characters or symbols.

cex

a numerical value giving the amount by which plotting text and symbols should be scaled relative to the default

lty

the line type, see par.

lwd

the line width not yet supported for postscript.

asp

the y/x aspect ratio, see plot.window.

...

graphical parameters as in par(...) may also be passed as arguments.

References

Cleveland, W. S. (1985) The Elements of Graphing Data. Monterey, CA: Wadsworth.

Examples

data(cars)
Speed <- cars$speed
Distance <- cars$dist
plot(Speed, Distance, panel.first = grid(8,8),
     pch = 0, cex = 1.2, col = "blue")
plot(Speed, Distance,
     panel.first = lines(lowess(Speed, Distance), lty = "dashed"),
     pch = 0, cex = 1.2, col = "blue")

##--- Log-Log Plot  with  custom axes
lx <- seq(1,5, length=41)
yl <- expression(e^{-frac(1,2) * {log[10](x)}^2})
y <- exp(-.5*lx^2)
op <- par(mfrow=c(2,1), mar=par("mar")+c(0,1,0,0))
plot(10^lx, y, log="xy", type="l", col="purple",
     main="Log-Log plot", ylab=yl, xlab="x")
plot(10^lx, y, log="xy", type="o", pch='.', col="forestgreen",
     main="Log-Log plot with custom axes", ylab=yl, xlab="x",
     axes = FALSE, frame.plot = TRUE)
axis(1, at = my.at <- 10^(1:5), labels = formatC(my.at, format="fg"))
at.y <- 10^(-5:-1)
axis(2, at = at.y, labels = formatC(at.y, format="fg"), col.axis="red")
par(op)