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   0.378   0.214
Method-ZZZ  Precision  0.595    0.843   0.77    0.689
Method-XZZZ Precision   0.573   0.698   0.53    0.708
Method-XZZZY    Precision   0.008   0.011   0.004   0.002
Method-XXX  Recall  0.9736842   0.9736842   0.9473684   0.9473684
Method-YYY     Recall   1   1   1   0.667
Method-ZZZ  Recall       0.833  1   1   1
Method-XZZZ Recall  1   1   1   1
Method-XZZZY    Recall  0.167   0.75    1   1

I can create this plot:

However as you can see, the x-axis are not all assigned with labels. How can I achieve that? It's also ok if we rotate the x-axis 45 degree. But then I'm not sure how to do that:

This is my code (Courtesy of thelatemail ):

dat <- read.table("http://dpaste.com/1563769/plain/",header=TRUE)
layout(matrix(c(1,2,5,3,4,5),nrow=2,byrow = TRUE))
barcols <- c("red","blue")

sapply(3:6, 
  function(x) {
    bp <- barplot(matrix(dat[,x],nrow=2,byrow=TRUE),beside=TRUE,col=barcols)
    title(main=names(dat[x]))
    axis(1,at=colMeans(bp),c("Method-XXX","Method-YYY"," Method-ZZZ","Method-XZZZ"," Method-XZZZY"),lwd=0,lwd.tick=1)
    abline(h=0)
  }
)

plot(NA,xlim=c(0,1),ylim=c(0,1),ann=FALSE,axes=FALSE)
legend(0,0.6,c("Precision","Recall"),fill=barcols,cex=1.5)

Update

I tried the following to generate the 45 degree. But didn't work either:

sapply(3:6,
  function(x) {
    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")
    text(cex=1, x=colMeans(bp)-.25, y=-1.25, xaxislab, xpd=TRUE, srt=45)
    #axis(1,at=colMeans(bp),xaxislab,lwd=0,lwd.tick=1)
    #abline(h=0)
  }
)
plot(NA,xlim=c(0,1),ylim=c(0,1),ann=FALSE,axes=FALSE)
legend(0,0.1,c("Precision","Recall"),fill=barcols,cex=1.5)

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)

Answer 2

With the reshape2 (for reshaping your data into long format) and ggplot2 (for plotting) packages, it will be quite a lot easier to make such a plot.

The code:

dat <- read.table("http://dpaste.com/1563769/plain/",header=TRUE)

library(reshape2)
library(ggplot2)

# reshape your data into long format
long <- melt(dat, id=c("Method","Metric"), 
             measure=c("E0","E1","E2","E4"),
             variable = "E.nr")

# make the plot
ggplot(long) +
  geom_bar(aes(x = Method, y = value, fill = Metric), 
           stat="identity", position = "dodge", width = 0.7) +
  facet_wrap(~E.nr) +
  scale_fill_manual("Metric\n", values = c("red","blue"), 
                    labels = c(" Precision", " Recall")) +
  labs(x="",y="") +
  theme_bw() +
  theme(
    panel.grid.major.y = element_line(colour = "black", linetype = 3, size = .5),
    panel.background = element_blank(),
    axis.title.x = element_text(size=16),
    axis.text.x = element_text(size=14, angle=45, hjust=1, vjust=1),
    axis.title.y = element_text(size=16, angle = 90),
    axis.text.y = element_text(size=14),
    strip.background = element_rect(color="white", fill="white"),
    strip.text = element_text(size=16)
  )

The result:

When you want to keep axis-labels on each seperate plot, you'll need the ggplot2 and gridExtra packages.

The code:

dat <- read.table("http://dpaste.com/1563769/plain/",header=TRUE)

library(ggplot2)
library(gridExtra)

# making the seperate plots 
pE0 <- ggplot(dat) +
  geom_bar(aes(x = Method, y = E0, fill = Metric), 
           stat="identity", position = "dodge", width = 0.7) +
  scale_fill_manual("Metric\n", values = c("red","blue"), 
                    labels = c(" Precision", " Recall")) +
  labs(title="E0\n",x="",y="") +
  theme_bw() +
  theme(
    panel.grid.major.y = element_line(colour = "black", linetype = 3, size = .5),
    panel.background = element_blank(),
    axis.title.x = element_text(size=16),
    axis.text.x = element_text(size=14, angle=30, hjust=1, vjust=1),
    axis.title.y = element_text(size=16, angle = 90),
    axis.text.y = element_text(size=14)
  )

pE1 <- ggplot(dat) +
  geom_bar(aes(x = Method, y = E1, fill = Metric), 
           stat="identity", position = "dodge", width = 0.7) +
  scale_fill_manual("Metric\n", values = c("red","blue"), 
                    labels = c(" Precision", " Recall")) +
  labs(title="E1\n",x="",y="") +
  theme_bw() +
  theme(
    panel.grid.major.y = element_line(colour = "black", linetype = 3, size = .5),
    panel.background = element_blank(),
    axis.title.x = element_text(size=16),
    axis.text.x = element_text(size=14, angle=30, hjust=1, vjust=1),
    axis.title.y = element_text(size=16, angle = 90),
    axis.text.y = element_text(size=14)
  )

pE2 <- ggplot(dat) +
  geom_bar(aes(x = Method, y = E2, fill = Metric), 
           stat="identity", position = "dodge", width = 0.7) +
  scale_fill_manual("Metric\n", values = c("red","blue"), 
                    labels = c(" Precision", " Recall")) +
  labs(title="E2\n",x="",y="") +
  theme_bw() +
  theme(
    panel.grid.major.y = element_line(colour = "black", linetype = 3, size = .5),
    panel.background = element_blank(),
    axis.title.x = element_text(size=16),
    axis.text.x = element_text(size=14, angle=30, hjust=1, vjust=1),
    axis.title.y = element_text(size=16, angle = 90),
    axis.text.y = element_text(size=14)
  )

pE4 <- ggplot(dat) +
  geom_bar(aes(x = Method, y = E4, fill = Metric), 
           stat="identity", position = "dodge", width = 0.7) +
  scale_fill_manual("Metric\n", values = c("red","blue"), 
                    labels = c(" Precision", " Recall")) +
  labs(title="E4\n",x="",y="") +
  theme_bw() +
  theme(
    panel.grid.major.y = element_line(colour = "black", linetype = 3, size = .5),
    panel.background = element_blank(),
    axis.title.x = element_text(size=16),
    axis.text.x = element_text(size=14, angle=30, hjust=1, vjust=1),
    axis.title.y = element_text(size=16, angle = 90),
    axis.text.y = element_text(size=14)
  )

# function to extract the legend (borrowed from: https://github.com/hadley/ggplot2/wiki/Share-a-legend-between-two-ggplot2-graphs )
g_legend<-function(a.gplot){
  tmp <- ggplot_gtable(ggplot_build(a.gplot))
  leg <- which(sapply(tmp$grobs, function(x) x$name) == "guide-box")
  legend <- tmp$grobs[[leg]]
  return(legend)}

legend <- g_legend(pE1)
lwidth <- sum(legend$width)

# combining the plots with gridExtra
grid.arrange(arrangeGrob(pE0 + theme(legend.position="none"),
                         pE1 + theme(legend.position="none"),
                         pE2 + theme(legend.position="none"),
                         pE4 + theme(legend.position="none")
                         ), 
             legend, widths=unit.c(unit(1, "npc") - lwidth, lwidth), nrow=1)

The result:

Answer 3

Here's a way to get all the labels without rotating. You plot the axis labels on two lines instead of one to avoid overlap. I've done it with a single graph to demonstrate the method.

dat <- read.table("http://dpaste.com/1563769/plain/",header=TRUE)

# Create barplot
barplot(height=dat$E0, beside=TRUE, col=c("red","blue"))

# Get x-coordinates of bars
x.coords = barplot(height=dat$E0, beside=TRUE, plot=FALSE)
# Create new coordinates between each pair of bars
new.x.coords = seq(sum(x.coords)[1:2]/2, sum(x.coords)[9:10]/2, x.coords[2]-x.coords[1])

# Plot axis labels, but not axis or tickmarks
axis(side=1, at=new.x.coords[c(1,3,5)], labels=dat$Method[c(1,3,5)], line=0, tick=FALSE)
axis(side=1, at=new.x.coords[c(2,4)], labels=dat$Method[c(2,4)], line=1, tick=FALSE)
# Plot just axis and tickmarks, but not labels
axis(side=1, at=new.x.coords, labels=NA)

Answer 4

add to rotate 45 degrees

dat <- read.table("http://dpaste.com/1563769/plain/",header=TRUE)
layout(matrix(c(1,2,5,3,4,5),nrow=2,byrow = TRUE))
barcols <- c("red","blue")

sapply(3:6, 
       function(x) {
         #par(las = 2)
         bp <- barplot(matrix(dat[,x],nrow=2,byrow=TRUE),beside=TRUE,col=barcols)
         title(main=names(dat[x]))
        #axis(1,at=colMeans(bp),lwd=0,lwd.tick=1,srt=45)
        text(colMeans(bp), par("usr")[3] , labels = c("Method-XXX","Method-YYY"," Method-ZZZ","Method-XZZZ"," Method-XZZZY"), srt = 45, pos = 1, xpd = TRUE)


         abline(h=0)
       }
)

plot(NA,xlim=c(0,1),ylim=c(0,1),ann=FALSE,axes=FALSE)
legend(0,0.6,c("Precision","Recall"),fill=barcols,cex=1.5)

add this to rotate 180 degrees the labels par(las = 2)

dat <- read.table("http://dpaste.com/1563769/plain/",header=TRUE)
    layout(matrix(c(1,2,5,3,4,5),nrow=2,byrow = TRUE))
    barcols <- c("red","blue")

sapply(3:6, 
       function(x) {
#add this to rotate the labels
         par(las = 2)
         bp <- barplot(matrix(dat[,x],nrow=2,byrow=TRUE),beside=TRUE,col=barcols)
         title(main=names(dat[x]))
         axis(1,at=colMeans(bp),c("Method-XXX","Method-YYY"," Method-ZZZ","Method-XZZZ"," Method-XZZZY"),lwd=0,lwd.tick=1)
         abline(h=0)
       }
)

plot(NA,xlim=c(0,1),ylim=c(0,1),ann=FALSE,axes=FALSE)
legend(0,0.6,c("Precision","Recall"),fill=barcols,cex=1.5)