plot.default
The Default Scatterplot Function
Draw a scatter plot with decorations such as axes and titles in the active graphics window.
- Keywords
- hplot
Usage
# S3 method for default
plot(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, asp = NA,
xgap.axis = NA, ygap.axis = NA,
…)
Arguments
- x, y
the
x
andy
arguments provide the x and y coordinates for the plot. Any reasonable way of defining the coordinates is acceptable. See the functionxy.coords
for details. If supplied separately, they must be of the same length.- type
1-character string giving the type of plot desired. The following values are possible, for details, see
plot
:"p"
for points,"l"
for lines,"b"
for both points and lines,"c"
for empty points joined by lines,"o"
for overplotted points and lines,"s"
and"S"
for stair steps and"h"
for histogram-like vertical lines. Finally,"n"
does not produce any points or lines.- xlim
the x limits (x1, x2) of the plot. Note that
x1 > x2
is allowed and leads to a ‘reversed axis’.The default value,
NULL
, indicates that the range of the finite values to be plotted should be used.- 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, see also
title
.- sub
a sub title for the plot.
- xlab
a label for the x axis, defaults to a description of
x
.- ylab
a label for the y axis, defaults to a description of
y
.- 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 both axes should be drawn on the plot. Use graphical parameter
"xaxt"
or"yaxt"
to suppress just one of the axes.- 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. Note that this works by lazy evaluation: passing this argument from other
plot
methods may well not work since it may be evaluated too early.- panel.last
an expression to be evaluated after plotting has taken place but before the axes, title and box are added. See the comments about
panel.first
.- asp
the \(y/x\) aspect ratio, see
plot.window
.- xgap.axis, ygap.axis
the \(x/y\) axis gap factors, passed as
gap.axis
to the twoaxis()
calls (whenaxes
is true, as per default).- …
other graphical parameters (see
par
and section ‘Details’ below).
Details
Commonly used graphical parameters are:
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. Lines will all be plotted in the first colour specified.
bg
a vector of background colors for open plot symbols, see
points
. Note: this is not the same setting aspar("bg")
.pch
a vector of plotting characters or symbols: see
points
.cex
a numerical vector giving the amount by which plotting characters and symbols should be scaled relative to the default. This works as a multiple of
par("cex")
.NULL
andNA
are equivalent to1.0
. Note that this does not affect annotation: see below.lty
a vector of line types, see
par
.cex.main
,col.lab
,font.sub
, etcsettings for main- and sub-title and axis annotation, see
title
andpar
.lwd
a vector of line widths, see
par
.
Note
The presence of panel.first
and panel.last
is a
historical anomaly: default plots do not have ‘panels’, unlike
e.g.pairs
plots. For more control, use lower-level
plotting functions: plot.default
calls in turn some of
plot.new
, plot.window
,
plot.xy
, axis
, box
and
title
, and plots can be built up by calling these
individually, or by calling plot(type = "n")
and adding further
elements.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
Cleveland, W. S. (1985) The Elements of Graphing Data. Monterey, CA: Wadsworth.
Murrell, P. (2005) R Graphics. Chapman & Hall/CRC Press.
See Also
plot
, plot.window
, xy.coords
.
For thousands of points, consider using smoothScatter
instead.
Examples
library(graphics)
# NOT RUN {
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(stats::lowess(Speed, Distance), lty = "dashed"),
pch = 0, cex = 1.2, col = "blue")
## Show the different plot types
x <- 0:12
y <- sin(pi/5 * x)
op <- par(mfrow = c(3,3), mar = .1+ c(2,2,3,1))
for (tp in c("p","l","b", "c","o","h", "s","S","n")) {
plot(y ~ x, type = tp, main = paste0("plot(*, type = \"", tp, "\")"))
if(tp == "S") {
lines(x, y, type = "s", col = "red", lty = 2)
mtext("lines(*, type = \"s\", ...)", col = "red", cex = 0.8)
}
}
par(op)
##--- 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(1,0,2,0), mgp = c(2, .7, 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)
my.at <- 10^(1:5)
axis(1, at = my.at, labels = formatC(my.at, format = "fg"))
e.y <- -5:-1 ; at.y <- 10^e.y
axis(2, at = at.y, col.axis = "red", las = 1,
labels = as.expression(lapply(e.y, function(E) bquote(10^.(E)))))
par(op)
# }