(This article was first published on

**Stat Bandit » R**, and kindly contributed to R-bloggers)Forest plots are most commonly used in reporting meta-analyses, but can be profitably used to summarise the results of a fitted model. They essentially display the estimates for model parameters and their corresponding confidence intervals.

Matt Shotwell just posted a message to the R-help mailing list with his *lattice*-based solution to the problem of creating forest plots in R. I just figured out how to create a forest plot for a consulting report using ggplot2. The availability of the `geom_pointrange`

layer makes this process very easy!!

credplot.gg <- function(d){ # d is a data frame with 4 columns # d$x gives variable names # d$y gives center point # d$ylo gives lower limits # d$yhi gives upper limits require(ggplot2) p <- ggplot(d, aes(x=x, y=y, ymin=ylo, ymax=yhi))+geom_pointrange()+ coord_flip() + geom_hline(aes(x=0), lty=2)+ xlab('Variable') return(p) }

If we start with some dummy data, like

d <- data.frame(x = toupper(letters[1:10]), y = rnorm(10, 0, 0.1)) d <- transform(d, ylo = y-1/10, yhi=y+1/10) credplot.gg(d)

To

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