CODEWITHSUNDEEP
rtexttext-alignment
ATMathew
ATMathew

Reputation: 12856

Align text inside a plot

I am an R newbie and had a question. I am trying to place some text into an R plot. Here's some code using the brightness dataset in the UsingR package.

    library(UsingR)
    brightness

    MyMean <- mean(brightness)
    MyMedian <- median(brightness)
    MySd <- sd(brightness)

    hist(brightness, breaks=35, main="This is a Histogram", 
         xlab="Brightness", ylab="Frequency", xlim=c(0,15), ylim=c(0, 200))

    text(3.5, 150, paste("Mean =", round(MyMean, 1), "\n Median =", 
         round(MyMedian, 1), "\n Std.Dev =", round(MySd, 1)))

This code produces:

enter image description here

The issue with this output is that the text is not left left alligned. Does anyone know how to make the text left alligned.

Thanks.

Upvotes: 29

Views: 73962

Answers (2)

John
John

Reputation: 23758

While legend() is of course appropriate for legends, there is a general solution for all text. The trick is that the pos option not only sets the position of the text relative to the current location but it also sets justification. Above and Below are center justified. Setting pos to 2 makes the text right justified. When it is set to the right of the position (pos = 4) then it is left justified.

For left justified replace your text code with...

text(1.5, 150, paste("Mean =", round(MyMean, 1), "\nMedian =", 
         round(MyMedian, 1), "\nStd.Dev =", round(MySd, 1)), pos = 4)

and for right justified...

text(5.0, 150, paste("Mean = ", round(MyMean, 1), "\nMedian = ", 
        round(MyMedian, 1), "\nStd.Dev = ", round(MySd, 1), sep = ''), pos = 2)

Upvotes: 42

JoFrhwld
JoFrhwld

Reputation: 9037

Try using legend() instead of text()

legend(3.5, 150, legend = c(paste("Mean =", round(MyMean, 1)),
                            paste("Median =",round(MyMedian, 1)),
                            paste("Std.Dev =", round(MySd, 1))), 
                  bty = "n")

You'll have to play around with the position adjustment. You might consider not using xy coordinates at all, but replacing those two arguments with "topleft"

Upvotes: 15

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