How to show all the labels in X-axis 45 degree in R 2x2 bar plot

Question

With the following data:

Method  Metric  E0  E1  E2  E4
Method-XXX  Precision   0.9661017   0.9622642   1   0.9655172
Method-YYY  Precision   0.533   0.535           


        

Answer 1

Following basically the same strategy used in this answer (and demo'd in the first example in the gridBase vignette (pdf)) you could use grid.text() to annotate the base graphics output.

library(gridBase)

## Function that plots barplots with x-axes annotated with slanted
ff <- function(x) {
    barcols <- c("red","blue")

    ## Plot, suppressing the labels
    bp <- barplot(matrix(dat[,x], nrow = 2, byrow = TRUE), xaxt = "n",
                  beside = TRUE, col = barcols)
    title(main=names(dat[x]))
    xaxislab <- c("Method-XXX", "Method-YYY", " Method-ZZZ",
                  "Method-XZZZ", " Method-XZZZY")

    ## Compute x-axis coordinate at center of each group
    bp <- colMeans(bp) 

    ## Use gridBase to compute viewport coordinates and
    ## grid to push/pop viewports and add the labels
    vps <- baseViewports()
    pushViewport(vps$inner, vps$figure, vps$plot)
    grid.text(xaxislab,
        x = unit(bp, "native"), y = unit(-0.5, "lines"),
        just = "right", rot = 45, gp=gpar(cex=0.7))
    popViewport(3)
}

## Apply it to your data 
dat <- read.table("http://dpaste.com/1563769/plain/",header=TRUE)
layout(matrix(c(1,2,5,3,4,5),nrow=2,byrow = TRUE))
sapply(3:6, ff)