geom_path: Connect observations.

# geom_line() is suitable for time series ggplot(economics, aes(date, unemploy)) + geom_line() ggplot(economics_long, aes(date, value01, colour = variable)) +  geom_line()  # geom_step() is useful when you want to highlight exactly when # the y value chanes recent <- economics[economics$date > as.Date("2013-01-01"), ] ggplot(recent, aes(date, unemploy)) + geom_line() ggplot(recent, aes(date, unemploy)) + geom_step()  # geom_path lets you explore how two variables are related over time, # e.g. unemployment and personal savings rate m <- ggplot(economics, aes(unemploy/pop, psavert)) m + geom_path() m + geom_path(aes(colour = as.numeric(date)))  # Changing parameters ---------------------------------------------- ggplot(economics, aes(date, unemploy)) +  geom_line(colour = "red")  # Use the arrow parameter to add an arrow to the line # See ?arrow for more details c <- ggplot(economics, aes(x = date, y = pop)) c + geom_line(arrow = arrow()) c + geom_line(  arrow = arrow(angle = 15, ends = "both", type = "closed") )  # 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")  # NAs break the 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) ) ggplot(df, aes(x, y1)) + geom_point() + geom_line() ggplot(df, aes(x, y2)) + geom_point() + geom_line() ggplot(df, aes(x, y3)) + geom_point() + geom_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.out = 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)) # These work p + geom_line(linetype = 2) p + geom_line(aes(colour = group), linetype = 2) p + geom_line(aes(colour = x)) # But this doesn't should_stop(p + geom_line(aes(colour = x), linetype=2))