Stacked Bar Chart in R

A stacked bar chart extends the standard bar chart from looking at numeric values across one categorical variable to two. Each bar in a standard bar chart is divided into a number of sub-bars stacked end to end, each one corresponding to a level of the second categorical variable. This article discusses how one can be created using R.

The function used here to create a stacked bar chart is barplot().

Syntax: barplot(H,xlab,ylab,main, names.arg,col)

Parameters:

• H: is a vector or matrix containing numeric values used in a bar chart.
• xlab: is the label for the x-axis.
• ylab: is the label for the y-axis.
• main: is the title of the bar chart.
• names.arg: is a vector of names appearing under each bar.
• col: is used to give colors to the bars in the graph.

Returns: a barplot.

Approach

• Create data
• Pass the data to the barplot() function
• Pass appropriate arguments to the function
• Display plot

Example:

R

dat <- read.table(text = "A   B   C   D   E   F    G
1 10 80 30 90 70 60  90
2 20 50 70 50 40 10  40
3 60 80 80 60  60 30 160
4 20 40 70 80 20 10  70", header = TRUE)

barplot(as.matrix(dat))

Output:

Example 2: 

R

dat <- read.table(text ="ProdA ProdB ProdC ProdD
1 110 50 60 70
2 120 50 80 65", header= TRUE)

barplot(as.matrix(dat),col=c("gold3","red"))

Output: