geom_line {ggplot2} | R Documentation |
Connect observations, ordered by x value.
geom_line(mapping = NULL, data = NULL, stat = "identity", position = "identity", ...)
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 overlappling points on this layer |
... |
other arguments passed on to
|
geom_line
understands the following aesthetics (required aesthetics are in bold):
x
y
alpha
colour
linetype
size
geom_path
: connect observations in data
order, geom_segment
: draw line segments,
geom_ribbon
: fill between line and x-axis
# Summarise number of movie ratings by year of movie mry <- do.call(rbind, by(movies, round(movies$rating), function(df) { nums <- tapply(df$length, df$year, length) data.frame(rating=round(df$rating[1]), year = as.numeric(names(nums)), number=as.vector(nums)) })) p <- ggplot(mry, aes(x=year, y=number, group=rating)) p + geom_line() # Add aesthetic mappings p + geom_line(aes(size = rating)) p + geom_line(aes(colour = rating)) # Change scale p + geom_line(aes(colour = rating)) + scale_colour_gradient(low="red") p + geom_line(aes(size = rating)) + scale_size(range = c(0.1, 3)) # Set aesthetics to fixed value p + geom_line(colour = "red", size = 1) # Use qplot instead qplot(year, number, data=mry, group=rating, geom="line") # Using a time series qplot(date, pop, data=economics, geom="line") qplot(date, pop, data=economics, geom="line", log="y") qplot(date, pop, data=subset(economics, date > as.Date("2006-1-1")), geom="line") qplot(date, pop, data=economics, size=unemploy/pop, geom="line") # Use the arrow parameter to add an arrow to the line # See ?grid::arrow for more details c <- ggplot(economics, aes(x = date, y = pop)) # Arrow defaults to "last" library(grid) c + geom_line(arrow = arrow()) c + geom_line(arrow = arrow(angle = 15, ends = "both", type = "closed")) # See scale_date for examples of plotting multiple times series on # a single graph # A simple pcp example y2005 <- runif(300, 20, 120) y2010 <- y2005 * runif(300, -1.05, 1.5) group <- rep(LETTERS[1:3], each = 100) df <- data.frame(id = seq_along(group), group, y2005, y2010) library(reshape2) # for melt dfm <- melt(df, id.var = c("id", "group")) ggplot(dfm, aes(variable, value, group = id, colour = group)) + geom_path(alpha = 0.5)