r - Combining Bar and Line chart (double axis) in ggplot2

Question

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.

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

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")

Answer 1

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: