Combining Bar and Line chart (double axis) in ggplot2

23
votes

I have double-y-axis chart made in Excel. In Excel it requires only basic skills. What I'd like to do is to replicate this chart using the ggplot2 library in R.

enter image description here

I have already done this, but I need to plot Response on 2nd-y-axis.

enter image description here

I enclose reproducible code I've used:

#Data generation
Year <- c(2014, 2015, 2016)
Response <- c(1000, 1100, 1200)
Rate <- c(0.75, 0.42, 0.80)

df <- data.frame(Year, Response, Rate)

#Chart
library(ggplot2)

ggplot(df)  + 
  geom_bar(aes(x=Year, y=Response),stat="identity", fill="tan1", colour="sienna3")+
  geom_line(aes(x=Year, y=Rate),stat="identity")+
  geom_text(aes(label=Rate, x=Year, y=Rate), colour="black")+
  geom_text(aes(label=Response, x=Year, y=0.9*Response), colour="black")
2
rggplot2bar-chartlinechartyaxis

2 Answers

35
votes

First, scale Rate by Rate*max(df$Response) and modify the 0.9 scale of Response text.

Second, include a second axis via scale_y_continuous(sec.axis=...):

ggplot(df)  + 
    geom_bar(aes(x=Year, y=Response),stat="identity", fill="tan1", colour="sienna3")+
    geom_line(aes(x=Year, y=Rate*max(df$Response)),stat="identity")+
    geom_text(aes(label=Rate, x=Year, y=Rate*max(df$Response)), colour="black")+
    geom_text(aes(label=Response, x=Year, y=0.95*Response), colour="black")+
    scale_y_continuous(sec.axis = sec_axis(~./max(df$Response)))

Which yields:

enter image description here

-1
votes

Use the syntax label=scales::percent to make the secondary axis into percentage : Click Here for Output

library(ggplot2)
ggplot(df)  + 
  geom_bar(aes(x=Year, y=Response),stat="identity", fill="tan1", 
  colour="sienna3")+
  geom_line(aes(x=Year, y=Rate*max(df$Response)),stat="identity")+
  geom_text(aes(label=Rate, x=Year, y=Rate*max(df$Response)), colour="black")+
  geom_text(aes(label=Response, x=Year, y=0.95*Response), colour="black")+
  scale_y_continuous(sec.axis = sec_axis(~./max(df$Response),label=scales::percent))