Untitled

x-axis labels do not match bars
test <- as.matrix(read.csv(file="test4.csv",sep=",",head=TRUE))
test <- test[,2:ncol(test)]
pdf(file="test.pdf", height=4, width=6)
par(lwd = 0.3)
barplot(test, space=0.4, xaxt='n', ann=FALSE)
axis(1, cex.axis=0.25, las=2, at=1:ncol(test), space=0.4, labels=colnames(test))
dev.off()

xLabLocs <- barplot(test, space=0.4, xaxt='n', ann=FALSE)
axis(1, cex.axis=0.25, las=2, at=xLabLocs,
     space=0.4, labels=colnames(test))

Value:
     A numeric vector (or matrix, when ‘beside = TRUE’), say ‘mp’,
     giving the coordinates of _all_ the bar midpoints drawn, useful
     for adding to the graph.