Two logarithmic y axis histograms in one R studio diagram

Question

I am using RStudio to draw the histogram of the values in this data .

data = read.table("C:\\Test\\test.csv", header=TRUE, sep=",")
hist(data$a, breaks=100)
hist(data$b, breaks=100)

and got the following histograms:

But I want to:

1- have the y axis logged so that instead of values 0, 4000, 8000 and 12000 I'll have 0, 10, 100, 1000, 10000 and so on (log2 ie, 0, 1, 2, 4, 8, 16, ... is also useful).

2- Have the two diagrams in a single diagram (preferably with bars of two different colors/patterns). In the resulting diagram, the two bars for each x-value would be beside each other like this:

I tried this solution but got the following error:

NULL

Warning message: In (function () : Only one RStudio graphics

device is permitted

Answer 1

Here's how I did it:

## Create fake data
x <- c(rep(1, 100), rep(2, 20000), rep(3, 800), rep(4, 10000))
y <- c(rep(1, 10), rep(2, 1000), rep(3, 10000), rep(4, 2000))

## Plot x
hist.x <- hist(x, plot = FALSE)
hist.x$counts <- log10(hist.x$counts + 1)
plot(hist.x, col = rgb(0, 0, 1, 0.25))

## Plot y
hist.y <- hist(y, plot = FALSE)
hist.y$counts <- log10(hist.y$counts + 1)
plot(hist.y, col = rgb(1, 0, 0, 0.25), add = TRUE)

which results in this:

If you would like them to be next to each other, just add

par(mfrow = c(1, 2)) 

at the top and change the plot command for y to `

plot(hist.y, col = rgb(1, 0, 0, 0.25))

The resulting plot looks like this:

Answer 2

Here's the solution I devised inspired from Teja_K 's answer:

data = read.table("C:\\test\\test.csv", header=TRUE, sep=",")
par( mar=c(3.1, 5.1, 0, 0)) 
hist.x <- hist(data$a, plot = FALSE, breaks=50)
hist.x$counts <- log10(hist.x$counts + 1)
plot(hist.x, col = rgb(0, 0, 1, 0.99), main="", xlab="", ylab="", yaxt="n")
yAxesTitles=c(1, 10, 100, 1000, 10000)
axis(2, at=c(0, 1, 2, 3, 4),labels=yAxesTitles, col.axis="black", las=2)
mtext(side = 1, text = "Number", line = 2)
mtext(side = 2, text = "Frequency", line = 4)
# Adding the second diagram to the first one:
relocatedData=data$b+0.2
hist.y <- hist(relocatedData, plot = FALSE, breaks=50)
hist.y$counts <- log10(hist.y$counts + 1)
plot(hist.y, col = rgb(1, 0, 0, 0.99), main="", xlab="", ylab="", yaxt="n", add=TRUE)
legend(7.5, 4, c("a", "b"), lwd=c(1, 1), col=c(rgb(0, 0, 1, 0.99), rgb(1, 0, 0, 0.99)), pch = c(15, 15), pt.cex=2)

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And the result: