如何在R中的ggplot2中绘制步骤直方图？

Question

How can I plot a "step" or "staircase" histogram in ggplot2 in R? something like:

where width of each horizontal line represents the bin size (of the x-axis values) and the height corresponds to fraction of the data that falls in that bin (unlike the attached image where it is a probability density!). is there a way to do this with geom_histogram ?

Answer 1

Generate some data:

foo <- data.frame(bar=rnorm(100))

Histogram with step geom and counts on y-axis:

ggplot(foo,aes(x=bar)) + stat_bin(geom="step")

Histogram with step geom and density on y-axis:

ggplot(foo,aes(x=bar)) + stat_bin(aes(y=..density..),geom="step")

And with "fraction of data that falls into that bin":

ggplot(foo,aes(x=bar)) + stat_bin(aes(y=..count../sum(..count..)),geom="step")

Answer 2

Might be other, prettier ways to do this but here's one idea.

foo <- data.frame(bar = rnorm(100)) + theme_bw()
p <- ggplot(data = foo, aes(x = bar, y = ..count../sum(..count..))) ## or aes(x = bar, y = ..density..) if you want that
p + geom_histogram(size = 2, colour = "red", fill = "white") + geom_histogram(colour = "transparent", fill = "white")

Edit:

geom_histogram(size = 2, colour = "red", fill = "white") creates this

I edited the thickness of the outline to size = 2 to make the final output look nice. It looks awful at this stage. To remove the interior lines you add geom_histogram(colour = "transparent", fill = "white") which will draw another histogram on top covering the interior lines (and some of the outline which is why I think size = 2 looks nice)