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vcd (version 1.4-3)

grid_legend: Legend Function for grid Graphics

Description

This function can be used to add legends to grid-based plots.

Usage

grid_legend(x, y, pch = NA, col = par('col'), labels, frame = TRUE, hgap = unit(0.8, "lines"), vgap = unit(0.8, "lines"), default_units = "lines", gp = gpar(), draw = TRUE, title = NULL, just = 'center', lwd = NA, lty = NA, size = 1, gp_title = NULL, gp_labels = NULL, gp_frame = gpar(fill = "transparent"), inset = c(0, 0))

Arguments

x
character string "topright", "topleft", "bottomright", "bottomleft", "top", "bottom", "left", "right", "center" or x coordinate of the legend.
y
y coordinates of the legend.
pch
integer vector of plotting symbols, if any.
col
character vector of colors for the symbols.
labels
character vector of labels corresponding to the symbols.
frame
logical indicating whether the legend should have a border or not.
hgap
object of class "unit" specifying the space between symbols and labels.
vgap
object of class "unit" specifying the space between the lines.
default_units
character string indicating the default unit.
gp
object of class "gpar" used for the legend.
draw
logical indicating whether the legend be drawn or not.
title
character string indicating the plot's title.
just
justification of the legend relative to its (x, y) location. see ?viewport for more details.
lwd
positive number to set the line width. if specified lines are drawn.
lty
line type. if specified lines are drawn.
size
size of the group symbols (in char units).
gp_title
object of class "gpar" used for the title.
gp_labels
object of class "gpar" used for the labels.
gp_frame
object of class "gpar" used for the frame.
inset
numeric vector of length 2 specifying the inset of the legend in npc units, relative to the specified x and y coordinates.

Value

Invisibly, the legend as a "grob" object.

See Also

legend

Examples

Run this code
data("Lifeboats")
attach(Lifeboats)
ternaryplot(Lifeboats[,4:6],
  pch = ifelse(side == "Port", 1, 19),
  col = ifelse(side == "Port", "red", "blue"),
  id  = ifelse(men / total > 0.1, as.character(boat), NA),
  prop_size = 2,
  dimnames_position = "edge",
  main = "Lifeboats on Titanic")
grid_legend(0.8, 0.9, c(1, 19), c("red", "blue"),
  c("Port", "Starboard"), title = "SIDE")


grid.newpage()
pushViewport(viewport(height = .9, width = .9 ))
grid.rect(gp = gpar(lwd = 2, lty = 2))

grid_legend(x = unit(.05,'npc'),
            y = unit(.05,'npc'),
            just = c(0,0),
            pch = c(1,2,3),
            col = c(1,2,3),
            lwd=NA, 
            lty=NA,
            labels = c("b",'r','g'),
            title = NULL,
            gp=gpar(lwd=2, cex=1),
            hgap = unit(.8, "lines"),
            vgap = unit(.9, "lines"))

grid_legend(x = unit(1,'npc'),
            y = unit(1,'npc'),
            just = c(1,1),
            pch = NA,
            col = c(1,2,3,4),
            lwd=c(1,1,1,3), 
            lty=c(1,2,1,3),
            labels = c("black",'red','green','blue'),
            gp_labels = list(gpar(col = 1), gpar(col = 2), gpar(col = 3), gpar(col = 4)),
            title = NULL,
            gp=gpar(lwd=2, cex=1),
            hgap = unit(.8, "lines"),
            vgap = unit(.9, "lines"))

grid_legend(x = 'topleft',
            pch = c(1,NA,2,NA),
            col = c(1,2,3,4),
            lwd=NA, 
            lty=c(NA,2,NA,3),
            labels = c("black",'red','green','blue'),
            title = 'Some LONG Title',
            gp_title = gpar(col = 3),
            gp_frame = gpar(col = 4, lty = 2, fill = "transparent"),
            gp_labels = gpar(col = 6),
            gp=gpar(lwd=2, cex=2, col = 1),
            hgap = unit(.8, "lines"),
            vgap = unit(.9, "lines"))

grid_legend(x = .7,
            y = .7,
            pch = c(1,NA,2,NA),
            col = c(1,2,3,4),
            lwd=1, 
            lty=c(NA,2,NA,3),
            labels = c("black",'red','green','blue'),
            title = 'short T',
            gp=gpar(lwd=1, cex=.7,col = 1),
            hgap = unit(.8, "lines"),
            vgap = unit(.9, "lines"))

grid_legend(x = 'bottomright',
            pch = c(1,NA,2,NA),
            col = c(2),
            lwd=NA, 
            lty=c(NA,2,NA,3),
            labels = c("black",'red','green','blue'),
            title = NULL,
            gp=gpar(lwd=2, cex=1,col = 1),
            hgap = unit(.8, "lines"),
            vgap = unit(.9, "lines"))

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