How do I create a grouped bar chart on R using ggplot2 using this data?
Person Cats Dogs Mr. A 3 1 Mr. B 4 2
So that it shows that shows number of pets owned per person, with this layout Bar chart of pets
I have a text file with this data and have used read.delim to read the file on R.
I have used this code but it does not produce the bar plot I am looking for.
ggplot(data=pets, aes(x=Person, y=Cats, fill=Dogs)) + geom_bar(stat="identity", position=position_dodge())
I am new to R, any help would be appreciated.
Thanks in advance.
To prepare data for grouped bar plot, use melt() function of reshape2 package
I. Loading required packages
library(reshape2) library(ggplot2)
II. Creating data frame df
df <- data.frame(Person = c("Mr.A","Mr.B"), Cats = c(3,4), Dogs = c(1,2)) df # Person Cats Dogs # 1 Mr.A 3 1 # 2 Mr.B 4 2
III. Melting data using melt function
data.m <- melt(df, id.vars='Person') data.m # Person variable value # 1 Mr.A Cats 3 # 2 Mr.B Cats 4 # 3 Mr.A Dogs 1 3 4 Mr.B Dogs 2
IV. Grouped Bar plot by Person
ggplot(data.m, aes(Person, value)) + geom_bar(aes(fill = variable), width = 0.4, position = position_dodge(width=0.5), stat="identity") + theme(legend.position="top", legend.title = element_blank(),axis.title.x=element_blank(), axis.title.y=element_blank())
Legend on top, legend title removed, axis titles removed, adjusted bar widths and space between bars.
