| geom_path {ggplot2} | R Documentation |
Connect observations in original order
geom_path(mapping = NULL, data = NULL, stat = "identity", position = "identity", lineend = "butt", linejoin = "round", linemitre = 1, na.rm = FALSE, arrow = NULL, ...)
mapping |
The aesthetic mapping, usually constructed with
|
data |
A layer specific dataset - only needed if you want to override the plot defaults. |
stat |
The statistical transformation to use on the data for this layer. |
position |
The position adjustment to use for overlapping points on this layer |
lineend |
Line end style (round, butt, square) |
linejoin |
Line join style (round, mitre, bevel) |
linemitre |
Line mitre limit (number greater than 1) |
na.rm |
If |
arrow |
Arrow specification, as created by ?grid::arrow |
... |
other arguments passed on to |
geom_path understands the following aesthetics (required aesthetics are in bold):
x
y
alpha
colour
linetype
size
geom_line: Functional (ordered) lines;
geom_polygon: Filled paths (polygons);
geom_segment: Line segments
# Generate data
library(plyr)
myear <- ddply(movies, .(year), colwise(mean, .(length, rating)))
p <- ggplot(myear, aes(length, rating))
p + geom_path()
# Add aesthetic mappings
p + geom_path(aes(size = year))
p + geom_path(aes(colour = year))
# Change scale
p + geom_path(aes(size = year)) + scale_size(range = c(1, 3))
# Set aesthetics to fixed value
p + geom_path(colour = "green")
# Control line join parameters
df <- data.frame(x = 1:3, y = c(4, 1, 9))
base <- ggplot(df, aes(x, y))
base + geom_path(size = 10)
base + geom_path(size = 10, lineend = "round")
base + geom_path(size = 10, linejoin = "mitre", lineend = "butt")
# Use qplot instead
qplot(length, rating, data=myear, geom="path")
# Using economic data:
# How is unemployment and personal savings rate related?
qplot(unemploy/pop, psavert, data=economics)
qplot(unemploy/pop, psavert, data=economics, geom="path")
qplot(unemploy/pop, psavert, data=economics, geom="path", size=as.numeric(date))
# How is rate of unemployment and length of unemployment?
qplot(unemploy/pop, uempmed, data=economics)
qplot(unemploy/pop, uempmed, data=economics, geom="path")
qplot(unemploy/pop, uempmed, data=economics, geom="path") +
geom_point(data=head(economics, 1), colour="red") +
geom_point(data=tail(economics, 1), colour="blue")
qplot(unemploy/pop, uempmed, data=economics, geom="path") +
geom_text(data=head(economics, 1), label="1967", colour="blue") +
geom_text(data=tail(economics, 1), label="2007", colour="blue")
# geom_path removes missing values on the ends of a line.
# use na.rm = T to suppress the warning message
df <- data.frame(
x = 1:5,
y1 = c(1, 2, 3, 4, NA),
y2 = c(NA, 2, 3, 4, 5),
y3 = c(1, 2, NA, 4, 5),
y4 = c(1, 2, 3, 4, 5))
qplot(x, y1, data = df, geom = c("point","line"))
qplot(x, y2, data = df, geom = c("point","line"))
qplot(x, y3, data = df, geom = c("point","line"))
qplot(x, y4, data = df, geom = c("point","line"))
# Setting line type vs colour/size
# Line type needs to be applied to a line as a whole, so it can
# not be used with colour or size that vary across a line
x <- seq(0.01, .99, length=100)
df <- data.frame(x = rep(x, 2), y = c(qlogis(x), 2 * qlogis(x)), group = rep(c("a","b"), each=100))
p <- ggplot(df, aes(x=x, y=y, group=group))
# Should work
p + geom_line(linetype = 2)
p + geom_line(aes(colour = group), linetype = 2)
p + geom_line(aes(colour = x))
# Should fail
should_stop(p + geom_line(aes(colour = x), linetype=2))
# Use the arrow parameter to add an arrow to the line
# See ?grid::arrow for more details
library(grid)
c <- ggplot(economics, aes(x = date, y = pop))
# Arrow defaults to "last"
c + geom_path(arrow = arrow())
c + geom_path(arrow = arrow(angle = 15, ends = "both", length = unit(0.6, "inches")))