Exact number of bins in Histogram in R
Solution 1
Use the breaks argument:
hist(data, breaks=seq(0,80,l=6),
freq=FALSE,col="orange",main="Histogram",
xlab="x",ylab="f(x)",yaxs="i",xaxs="i")
Solution 2
The integer specified as argument for nclass
is used as a suggestion:
the number is a suggestion only
An alternative solution is to cut
your vector into a specified number of groups and plot the result:
plot(cut(data, breaks = 4))
Solution 3
Building on the answer from Rob Hyndman:
Maybe a more generic solution would be to make the breaks considering the minimun and maximun values of the data, and the number of breaks = number_of_bins+1.
hist(data,breaks=seq(min(data),max(data),l=number_of_bins+1),
freq=FALSE,col="orange",
main="Histogram",xlab="x",ylab="f(x)",yaxs="i",xaxs="i")
Solution 4
I like to be quite accurate about my data points:
hist(data,breaks = seq(min(data),max(data),by=((max(data) - min(data))/(length(data)-1))))
This should automate the process with little manual input.
Solution 5
If you are not opposed to using something other than base graphics, there is always the ggplot2 way of doing things:
library(ggplot2)
data <- data.frame(x=data)
ggplot(data, aes(x=x))+
geom_histogram(binwidth=18,color="black", fill="grey")+
scale_x_continuous(breaks=c(0,20,40,60,80)
ggplot2 has great documentation at: https://ggplot2.tidyverse.org/
For histogram specific examples: https://ggplot2.tidyverse.org/reference/geom_histogram.html
Eduardo
Updated on April 16, 2020Comments
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Eduardo about 4 years
I'm having trouble making a histogram in R. The problem is that I tell it to make 5 bins but it makes 4 and I tell to make 5 and it makes 8 of them.
data <- c(5.28, 14.64, 37.25, 78.9, 44.92, 8.96, 19.22, 34.81, 33.89, 24.28, 6.5, 4.32, 2.77, 17.6, 33.26, 52.78, 5.98, 22.48, 20.11, 65.74, 35.73, 56.95, 30.61, 29.82); hist(data, nclass = 5,freq=FALSE,col="orange",main="Histogram",xlab="x",ylab="f(x)",yaxs="i",xaxs="i")
Any ideas on how to fix it?