How to create a stacked bar chart in r with ggplot-CodePudding

My data is:



positive <- c("21", "22", "33", "21", "27") ##Percentage
negative<- c("71", "77", "67", "79", "73")  ##Precentage 
sample <- c("Hr", "Fi", "We", "Pa", "Ki")
mydata <- data.frame(positive , negative, sample)

I want to create a stacked bar graph that shows positive and negative percentages for each category in the sample variable. I tried this:

ggplot(mydata)  
  geom_bar(aes(x = sample, fill = positive))

but did not wrok. Sorry if the question looks basic. I started R a few weeks ago.

CodePudding user response：

This probably serves your purpose:

library(tidyverse)
mydata %>% pivot_longer(cols = !sample, names_to = "status", values_to = "percentage") %>% 
 ggplot(aes(fill = status, x = sample, y = percentage))   
 geom_bar(position = "stack", stat = "identity")

The result:

CodePudding user response：

You need to pivot your data to long format first (tidy format). Then, we can specify the x (sample), y (value), and fill (name) conditions.

library(tidyverse)

mydata %>%
  pivot_longer(-sample) %>%
  ggplot(aes(fill = name, y = value, x = sample))  
  geom_bar(position = "stack", stat = "identity")

Output

CodePudding user response：

Here is an alternative approach using values_transform to get numeric type and then using geom_col with position_fill and percentage features:

library(dplyr)
library(tidyr)
library(ggplot)
library(scales)

mydata %>% 
  pivot_longer(
    cols = -sample,
    names_to = "status",
    values_to = "percentage", 
    values_transform = list(percentage = as.integer)
  ) %>% 
  ggplot(aes(x = sample, y=percentage, fill=status)) 
  geom_col(position = position_fill())  
  scale_y_continuous(labels = scales::percent)  
  geom_text(aes(label = percentage),
            position = position_fill(vjust = .5))