ACF Plot with ggplot2: Setting width of geom_bar

Question

With acf we can make ACF plot in base R graph.

x <- lh
acf(x)

The following code can be used to get the ACF plot in ggplot2.

conf.level <- 0.95
ciline <- qnorm((1 - conf.level)/2)/sqrt(length(x))
bacf <- acf(x, plot = FALSE)
bacfdf <- with(bacf, data.frame(lag, acf))

library(ggplot2)
q <- ggplot(data=bacfdf, mapping=aes(x=lag, y=acf)) +
       geom_bar(stat = "identity", position = "identity")
q

Question

How to get lines rather than bars or how to set the width of bars so that they look like lines? Thanks

Answer 1

You're probably better off plotting with line segments via geom_segment()

library(ggplot2)

set.seed(123)
x <- arima.sim(n = 200, model = list(ar = 0.6))

bacf <- acf(x, plot = FALSE)
bacfdf <- with(bacf, data.frame(lag, acf))

q <- ggplot(data = bacfdf, mapping = aes(x = lag, y = acf)) +
       geom_hline(aes(yintercept = 0)) +
       geom_segment(mapping = aes(xend = lag, yend = 0))
q

Answer 2

How about using geom_errorbar with width=0?

ggplot(data=bacfdf, aes(x=lag, y=acf)) + 
    geom_errorbar(aes(x=lag, ymax=acf, ymin=0), width=0)