R ggplot2 facet diagram using multiple variables

Question

I have a question regarding ggplot diagram that i cant solve, my struggle comes from the fact that i have to put multiple variables on the X axis and that I have to take the values for 2 different data frame.

Assume i am given the following 2 data frames:

Question<-c(1,2,3)
True<-c(30,20,10)
False<-c(10,15,20)
None<-c(3,2,3)
df1<-data.frame(Question, True, False, None)

Question<-c(1,2,3)
True<-c(20,20,15)
False<-c(20,15,5)
None<-c(3,2,2)
df2<-data.frame(Question, True, False, None)

df1 would look like this

Question  True  False None
1         30     10   3
2         20     15   2
3         15     5    2

And df2 would look similar

It is asked that i produce side by side chart comparing the distribution on df1 versus df2 for each question using a facet ggplot.

This plot needs to specifically look like this where Group 1 is from df1 and group 2 is from df2:

What it must look like

Thank you all

Answer 1

I would suggest this approach. With your dataframes you can create the Group variable, bind the data with rbind() and then reshape to have the desired variables in a format ready for the plot:

library(tidyverse)
#Data
Question<-c(1,2,3)
True<-c(30,20,10)
False<-c(10,15,20)
None<-c(3,2,3)
df1<-data.frame(Question, True, False, None)
#Data 2
Question<-c(1,2,3)
True<-c(20,20,15)
False<-c(20,15,5)
None<-c(3,2,2)
df2<-data.frame(Question, True, False, None)
#Bind data
df1$Group <- 'df1'
df2$Group <- 'df2'
dfg <- rbind(df1,df2)
#Reshape
dfg %>% pivot_longer(cols = -c(Question,Group)) %>%
  ggplot(aes(x=name,y=value,fill=Group))+
  geom_bar(stat = 'identity',position = position_dodge(0.9))+
  facet_wrap(.~Question)

Output: