forestplot.r

forestplot.r

# 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
forestplot <- function(d, xlab="Odds Ratio", ylab="Study"){
    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) +
		ylab(xlab) +
		xlab(ylab) #switch because of the coord_flip() above
    return(p)
}

# Create some dummy data.
d <- data.frame(x = toupper(letters[1:10]),
                y = rnorm(10, .05, 0.1))
d <- transform(d, ylo = y-1/10, yhi=y+1/10)

forestplot(d)

This doesn't work anymore with the new ggplot2.
I suggest the following change:

forestplot <- function(d, xlab="Odds Ratio", ylab="Study"){
        require(ggplot2)
        p <- ggplot(d, aes(x=x, y=y, ymin=ylo, ymax=yhi)) + 
                geom_pointrange() + 
                coord_flip() +
                geom_hline(yintercept = 1) +
                ylab(xlab) +
                xlab(ylab) #switch because of the coord_flip() above
        return(p)
}