| grid.arrows {grid} | R Documentation |
Functions to create and draw arrows at either end of a line, or at either end of a line.to, lines, or segments grob.
grid.arrows(x = c(0.25, 0.75), y = 0.5, default.units = "npc",
grob = NULL,
angle = 30, length = unit(0.25, "inches"),
ends = "last", type = "open", name = NULL,
gp = gpar(), draw = TRUE, vp = NULL)
arrowsGrob(x = c(0.25, 0.75), y = 0.5, default.units = "npc",
grob = NULL,
angle = 30, length = unit(0.25, "inches"),
ends = "last", type = "open", name = NULL,
gp = gpar(), vp = NULL)
x |
A numeric vector or unit object specifying x-values. |
y |
A numeric vector or unit object specifying y-values. |
default.units |
A string indicating the default units to use
if x or y are only given as numeric vectors. |
grob |
A grob to add arrows to; currently can only be a line.to, lines, or segments grob. |
angle |
A numeric specifying (half) the width of the arrow head (in degrees). |
length |
A unit object specifying the length of the arrow head. |
ends |
One of "first", "last", or "both",
indicating which end of the line to add arrow heads. |
type |
Either "open" or "closed" to indicate
the type of arrow head. |
name |
A character identifier. |
gp |
An object of class gpar, typically the output
from a call to the function gpar. This is basically
a list of graphical parameter settings. |
draw |
A logical value indicating whether graphics output should be produced. |
vp |
A Grid viewport object (or NULL). |
Both functions create an arrows grob (a graphical object describing
arrows), but only grid.arrows()
draws the arrows (and then only if draw is TRUE).
If the grob argument is specified, this overrides any x and/or y arguments.
An arrows grob. grid.arrows() returns the value invisibly.
Paul Murrell
Grid,
viewport,
grid.line.to,
grid.lines,
grid.segments
pushViewport(viewport(layout=grid.layout(2, 4)))
pushViewport(viewport(layout.pos.col=1,
layout.pos.row=1))
grid.rect(gp=gpar(col="grey"))
grid.arrows()
popViewport()
pushViewport(viewport(layout.pos.col=2,
layout.pos.row=1))
grid.rect(gp=gpar(col="grey"))
grid.arrows(angle=15, type="closed")
popViewport()
pushViewport(viewport(layout.pos.col=3,
layout.pos.row=1))
grid.rect(gp=gpar(col="grey"))
grid.arrows(angle=5, length=unit(0.1, "npc"),
type="closed", gp=gpar(fill="white"))
popViewport()
pushViewport(viewport(layout.pos.col=4,
layout.pos.row=1))
grid.rect(gp=gpar(col="grey"))
grid.arrows(x=unit(0:80/100, "npc"),
y=unit(1 - (0:80/100)^2, "npc"))
popViewport()
pushViewport(viewport(layout.pos.col=1,
layout.pos.row=2))
grid.rect(gp=gpar(col="grey"))
grid.arrows(ends="both")
popViewport()
pushViewport(viewport(layout.pos.col=2,
layout.pos.row=2))
grid.rect(gp=gpar(col="grey"))
# Recycling arguments
grid.arrows(x=unit(1:10/11, "npc"), y=unit(1:3/4, "npc"))
popViewport()
pushViewport(viewport(layout.pos.col=3,
layout.pos.row=2))
grid.rect(gp=gpar(col="grey"))
# Drawing arrows on a segments grob
gs <- segmentsGrob(x0=unit(1:4/5, "npc"),
x1=unit(1:4/5, "npc"))
grid.arrows(grob=gs, length=unit(0.1, "npc"),
type="closed", gp=gpar(fill="white"))
popViewport()
pushViewport(viewport(layout.pos.col=4,
layout.pos.row=2))
grid.rect(gp=gpar(col="grey"))
# Arrows on a lines grob
# Name these because going to grid.edit them later
gl <- linesGrob(name="curve", x=unit(0:80/100, "npc"),
y=unit((0:80/100)^2, "npc"))
grid.arrows(name="arrowOnLine", grob=gl, angle=15, type="closed",
gp=gpar(fill="black"))
popViewport()
pushViewport(viewport(layout.pos.col=1,
layout.pos.row=2))
grid.move.to(x=0.5, y=0.8)
popViewport()
pushViewport(viewport(layout.pos.col=4,
layout.pos.row=1))
# Arrows on a line.to grob
glt <- lineToGrob(x=0.5, y=0.2, gp=gpar(lwd=3))
grid.arrows(grob=glt, ends="first", gp=gpar(lwd=3))
popViewport(2)
grid.edit(gPath("arrowOnLine", "curve"), y=unit((0:80/100)^3, "npc"))