Connect observations in original order

Usage

geom_path(mapping = NULL, data = NULL, stat = "identity", position = "identity", 
  lineend = "butt", linejoin = "round", linemitre = 1, na.rm = FALSE, arrow = NULL, 
      ...)

Arguments

lineend
Line end style (round, butt, square)
linejoin
Line join style (round, mitre, bevel)
linemitre
Line mitre limit (number greater than 1)
arrow
Arrow specification, as created by ?grid::arrow
mapping
The aesthetic mapping, usually constructed with aes or aes_string. Only needs to be set at the layer level if you are overriding the plot defaults.
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 overlappling points on this layer
na.rm
If FALSE (the default), removes missing values with a warning. If TRUE silently removes missing values.
...
other arguments passed on to layer. This can include aesthetics whose values you want to set, not map. See layer for more details.

Description

Connect observations in original order

Aesthetics

geom_path understands the following aesthetics (required aesthetics are in bold):

  • x
  • y
  • alpha
  • colour
  • linetype
  • size

Examples

# 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"))
Warning message: Removed 1 rows containing missing values (geom_point). Warning message: Removed 1 rows containing missing values (geom_path).

qplot(x, y2, data = df, geom = c("point","line"))
Warning message: Removed 1 rows containing missing values (geom_point). Warning message: Removed 1 rows containing missing values (geom_path).

qplot(x, y3, data = df, geom = c("point","line"))
Warning message: Removed 1 rows containing missing values (geom_point).

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")))

See also

geom_line: Functional (ordered) lines; geom_polygon: Filled paths (polygons); geom_segment: Line segments