axis {base} | R Documentation |
Adds an axis to the current plot, allowing the specification of the side, position, labels, and other options.
axis(side, at = NULL, labels = TRUE, tick = TRUE, line = NA, pos = NA, outer = FALSE, font = NA, vfont = NULL, lty = "solid", lwd = 1, col = NULL, ...)
side |
an integer specifying which side of the plot the axis is to be drawn on. The axis is placed as follows: 1=below, 2=left, 3=above and 4=right. |
at |
the points at which tick-marks are to be drawn. Non-finite
(infinite, NaN or NA ) values are omitted. By default,
when NULL , tickmark locations are computed, see Details below. |
labels |
this can either be a logical value specifying whether (numerical) annotations are to be made at the tickmarks, or a vector of character strings to be placed at the tickpoints. |
tick |
a logical value specifying whether tickmarks should be drawn |
line |
the number of lines into the margin which the axis will
be drawn. This overrides the value of the graphical parameter
mgp[3] . The relative placing of tickmarks and tick labels
is unchanged. |
pos |
the coordinate at which the axis line is to be drawn.
this overrides the value of both line and mgp[3] . |
outer |
a logical value indicating whether the axis should be drawn in the outer plot margin, rather than the standard plot margin. |
font |
font for text. |
vfont |
vector font for text. |
lty, lwd |
line type, width for the axis line and the tick marks. |
col |
color for the axis line and the tick marks. The default
NULL means to use par("fg") . |
... |
other graphical parameters may also be passed as arguments to
this function, e.g., las for vertical/horizontal label
orientation, or fg instead of col , see
par on these. |
The axis line is drawn from the lowest to the highest value of
at
, but will be clipped at the plot region. Only ticks which
are drawn from points within the plot region (up to a tolerance for
rounding error) are plotted, but the ticks and their labels may well
extend outside the plot region.
When at = NULL
, pretty tick mark locations are computed internally,
from par("usr","lab")
, and par("xlog")
(or
ylog
respectively).
This function is invoked for its side effect, which is to add an axis to an already existing plot.
plot(1:4, rnorm(4), axes=FALSE) axis(1, 1:4, LETTERS[1:4]) axis(2) box() #- to make it look "as usual" plot(1:7, rnorm(7), main = "axis() examples", type = "s", xaxt="n", frame = FALSE, col = "red") axis(1, 1:7, LETTERS[1:7], col.axis = "blue") # unusual options: axis(4, col = "violet", col.axis="dark violet",lwd = 2) axis(3, col = "gold", lty = 2, lwd = 0.5)