code from blog post to make a volcano plot

volcanoplot.r

# Download the data from github (click the "raw" button, save as a text file called "results.txt").
# https://gist.github.com/stephenturner/806e31fce55a8b7175af
res <- read.table("results.txt", header=TRUE)
head(res)

# Make a basic volcano plot
with(res, plot(log2FoldChange, -log10(pvalue), pch=20, main="Volcano plot", xlim=c(-2.5,2)))

# Add colored points: red if padj<0.05, orange of log2FC>1, green if both)
with(subset(res, padj<.05 ), points(log2FoldChange, -log10(pvalue), pch=20, col="red"))
with(subset(res, abs(log2FoldChange)>1), points(log2FoldChange, -log10(pvalue), pch=20, col="orange"))
with(subset(res, padj<.05 & abs(log2FoldChange)>1), points(log2FoldChange, -log10(pvalue), pch=20, col="green"))

# Label points with the textxy function from the calibrate plot
library(calibrate)
with(subset(res, padj<.05 & abs(log2FoldChange)>1), textxy(log2FoldChange, -log10(pvalue), labs=Gene, cex=.8))

Thanks

When labeling points, is there a way to keep the labels from overlapping?