library(ggplot2)
program 4
4. develop a script in R to produce a bar graph displaying the frequency distribution of categorical data in a given dataset,grouped by a specified variable,using ggplot2.
step1:load the dataset
<-mtcars
datahead(data)
mpg cyl disp hp drat wt qsec vs am gear carb
Mazda RX4 21.0 6 160 110 3.90 2.620 16.46 0 1 4 4
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875 17.02 0 1 4 4
Datsun 710 22.8 4 108 93 3.85 2.320 18.61 1 1 4 1
Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
Hornet Sportabout 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2
Valiant 18.1 6 225 105 2.76 3.460 20.22 1 0 3 1
step2:Convert Numeric Data to categorical
$cyl<-as.factor(data$cyl)
data$gear<-as.factor(data$gear) data
step3:
ggplot(data, aes(x = cyl , fill = gear))+
geom_bar(position = "dodge")+
labs(title = "Frequency of cylinder Grouped by Gear Type",
x = "number of cylinders",
y = "count",
fill = "Gears")+
theme_minimal()