How how to make a histogram with two colors for each bin?

February 9, 2022

I have a data frame with the names of articles, number of samples overall for each article, number of responders for a drug and number of non-responders. All togther there are 9 articles:

Articles <- c("Nadeem Riaz", "David Braun","immotion150", "IMVIGOR210", "Alexander Lozano",
             "Van Allen", "Alexandra Pender", "David Lui", "Jae Cho")
Samples_number <- c(49, 311, 247, 298, 47, 39, 82, 121, 16)
With_Benefit <- c(26, 89, 168, 131, 27, 13,17,65, 5)
No_Benefit <- c(13, 102, 79, 167, 20, 26, 65, 56, 11)

MyData <- data.frame(Articles, Samples_number, With_Benefit, No_Benefit)

I need to make a histogram with the Articles Names on the x axis, the overall samples number on the y axis, and color each bin so that for example responders would be blue and non-responders red, for each article.

I built a histogram I just don’t know what to type in the fill segment: (here I just typed the No_Benefit column but I know it’s a wrong fill)

myplot <- ggplot(MyData, aes(x = Articles, y = Samples_number, fill= No_Benefit)) + theme_bw() + geom_col(position = "stack")
print(myplot)

Thank you.

>Solution :

I believe the main problem is with the format of the dataframe; your data is in ‘wide’ format, but ggplot2 works a lot better with ‘long’ format. You can pivot your dataframe from ‘wide’ to ‘long’ with the pivot_longer() function from the tidyr package, e.g.

library(ggplot2)
library(tidyr)

Articles <- c("Nadeem Riaz", "David Braun","immotion150", "IMVIGOR210", "Alexander Lozano",
              "Van Allen", "Alexandra Pender", "David Lui", "Jae Cho")
Samples_number <- c(49, 311, 247, 298, 47, 39, 82, 121, 16)
With_Benefit <- c(26, 89, 168, 131, 27, 13,17,65, 5)
No_Benefit <- c(13, 102, 79, 167, 20, 26, 65, 56, 11)

MyData <- data.frame(Articles, Samples_number, With_Benefit, No_Benefit)

MyData_long <- pivot_longer(MyData, -c(Articles, Samples_number), names_to = "response")

ggplot(MyData_long, aes(x = Articles, y = Samples_number, fill= response)) +
  theme_bw() +
  geom_col(position = "stack")