Draw frequency density histogram in R

Question

Using R, can anyone show me how to draw a simple histogram with no gaps between the bins of the following data :-

Class Width Freq. Dist

0 <= x < 5          0.2 
5 <= x < 15         0.1
15 <= x < 20        1.2
20 <= x < 30        0.4
30 <= x < 40        0.4

So I want the X axis to go from 0-5,5-15,15-20,20-30 and 30-40 with the bars drawn appropriately.

Thanks in advance !

Answer 1

How about this one?

breaks <- c(0,5,15,20,30,40)
counts <- c(0.2, 0.1, 1.2, 0.4, 0.4)
barplot(counts,
   names=sprintf("[%g,%g)",
      breaks[-length(breaks)], breaks[-1]
   ),
   space=0
)

This will give you bars of equal widths. On the other hand, If you'd like to obtain bars of various widths, type:

barplot(counts, diff(breaks),
    names=sprintf("[%g,%g)", breaks[-length(breaks)], breaks[-1]),
    space=0
)

Moreover, this will give you an "ordinary" X axis:

barplot(counts, diff(breaks), space=0)
axis(1)

And if you'd like to get axis breaks exactly at points in breaks, type:

axis(1, at=breaks)

Answer 2

I would look into the "HistogramTools" package for R.

breaks <- c(0, 5, 15, 20, 30, 40)
counts <- c(0.2, 0.1, 1.2, 0.4, 0.4)
library(HistogramTools)
plot(PreBinnedHistogram(breaks, counts), main = "")