segments(x1, y1, x2=x1, y2=y1, ..., subset, zero=T) arrows(x1, y1, x2=x1, y2=y1, size=.2, open=F, rel=F, ..., subset)
(x1[i],y1[i])
to
(x2[i],y2[i])
.
x2
and
y2
may be omitted, in which case they default to
x1
and
y1
, for vertical or horizontal lines, respectively.
Missing values (NA) are allowed.
Any segments with any
NA
s as end-points will not be drawn.
rel
is
TRUE
.
If
rel
is
FALSE
,
size
is arrowhead width in inches.
TRUE
the arrowhead is "v" shaped, if
FALSE
it is triangular.
TRUE
then arrowheads are sized relative to the length of the
arrow.
x1
,
y1
,
x2
, and
y2
to use.
FALSE
then zero-length segments are
not drawn. If
TRUE
then zero-length segments
are drawn, typically appearing as a single pixel
(except on some graphics devices no point appears if graphics
parameters such as
lwd
or
lty
are supplied).
Adds line segments or arrows to the current plot from coordinates
x1,y1
to coordinates
x2,y2
. End points specified as
NA
do
not have the arrows or line segments printed.
x <- 1:5 y <- c(5,3,2,4,1) plot(x,y) # draw arrows from 'i'th to 'i+1'st points s <- seq(length(x)-1) # sequence one shorter than x arrows(x[s], y[s], x[s+1], y[s+1]) # horizontal and vertical segments, and subset segments(x, y, x+.5, col=2, subset=1:3) segments(x, y, y2 = y-.5, col=3, subset=1:3) # a function to make plots with error bars errorbar <- function(x, y, plusmin) { plot(x, y, ylim = c(min(y - plusmin), max(y + plusmin))) segments(x, y + plusmin, y2 = y - plusmin) }