Depicting groups of numerical data- Boxplot, Violin plot, and Sinaplot plot

The EDA of gapminder data can be found at the following link

https://trungmdang.wixsite.com/website/post/revisiting-the-gapminder-dataset-using-dplyr-and-ggplot2

library(ggplot2)
library(tidyverse)

## -- Attaching packages --------------------------------------- tidyverse 1.3.0 --

## v tibble  3.0.5     v dplyr   1.0.3
## v tidyr   1.1.2     v stringr 1.4.0
## v readr   1.4.0     v forcats 0.5.0
## v purrr   0.3.4

## -- Conflicts ------------------------------------------ tidyverse_conflicts() --
## x dplyr::filter() masks stats::filter()
## x dplyr::lag()    masks stats::lag()

library(gapminder)
library(dplyr)

1. Basics

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp)) +
  geom_boxplot()

2. Controlling colors

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp)) +
  geom_boxplot(color = "orange",
               fill = "orange",
               alpha = 0.2,              
               notchwidth = 0.8,
               outlier.colour=  "blue",
               outlier.fill= "blue",
               outlier.size = 3)

Set a different color for each group

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp)) +
  geom_boxplot(aes(color = continent))+ # color = continent
  scale_color_manual(values = c("#00AFBB", "#E7B800", "#FC4E07","blue")) # scale_color_manual

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp)) +
  geom_boxplot(aes(fill = continent))+ # fill = continent
  scale_fill_manual(values = c("#00AFBB", "#E7B800", "#FC4E07","blue")) # scale_fill_manual

Highlighting a group of interest

mpg %>% mutate(type = ifelse(class=="subcompact","Highlighted","Normal")) %>% 
  ggplot(aes(x = class, 
             y = hwy, 
             fill = type)) + 
  geom_boxplot() +
  scale_fill_manual(values=c("blue", "grey")) +
  theme(axis.title.x= element_blank(),
        legend.position = "none")

3. Notched box plots

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp)) +
  geom_boxplot(color = "orange",
               fill = "orange",
               alpha = 0.2, 
               notch = TRUE,
               notchwidth = 0.8,
               outlier.colour=  "blue",
               outlier.fill= "blue",
               outlier.size = 3)

Notched box plot with mean points

gapminder %>% 
  filter(continent != "Oceania") %>% 
ggplot(aes(x = continent, 
                y = lifeExp)) +
  geom_boxplot(color = "orange",
               fill = "orange",
               alpha = 0.2, #
               notch = TRUE,
               notchwidth = 0.8,
               outlier.colour=  "blue",
               outlier.fill= "blue",  
               outlier.size = 5) +
  stat_summary(fun = mean,
               geom = "point",
               shape = 18,
               size = 5,
               color = "blue")

4. Violin plots

library(Hmisc)

## Loading required package: lattice

## Loading required package: survival

## Loading required package: Formula

## 
## Attaching package: 'Hmisc'

## The following objects are masked from 'package:dplyr':
## 
##     src, summarize

## The following objects are masked from 'package:base':
## 
##     format.pval, units

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp)) +
  geom_violin(trim = FALSE, 
              aes(color = continent)) +
  stat_summary(fun.data = "mean_sdl",  
               fun.args = list(mult = 1), 
               geom = "pointrange", 
               color = "black") +
  scale_color_manual(values = c("#00AFBB", "#E7B800", "#FC4E07","blue"))

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp)) +
  geom_violin(aes(fill = continent), trim = FALSE) + 
  geom_boxplot(width = 0.15)+
  scale_fill_manual(values = c("#00AFBB", "#E7B800", "#FC4E07","blue")) +
  theme(legend.position = "none")

5. Sinaplot

library(ggforce)

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp)) +
  geom_sina(aes(color = continent), size = 1)+
  scale_color_manual(values = c("#00AFBB", "purple", "#FC4E07","blue")) +
  theme(legend.position = "none")

6. Changing the order of display

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp)) +
  geom_boxplot(aes(fill = continent))+ 
  scale_fill_manual(values = c("#00AFBB", "#E7B800", "#FC4E07","blue"))+
  scale_x_discrete(limits=c("Africa", "Asia","Americas","Europe")) 

7. Grouped boxplot

gapminder %>% 
  filter(year %in% c(1957,1987,2007) & continent != "Oceania") %>%
  ggplot(aes(x = continent, 
             y = lifeExp, 
             fill = factor(year))) + # the variable year is int, this variable must be converted into factor.
  geom_boxplot() +
  theme(axis.title.x= element_blank(),
        legend.position = "none")

Using facet in ggplot

gapminder %>% 
  filter(continent != "Oceania") %>% 
  ggplot(aes(x = continent, 
             y = lifeExp, 
             fill = continent)) +
  geom_boxplot() +
  facet_wrap(~year) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1),
        axis.title.x= element_blank(),
        legend.position = "none")

Split the plot into multiple panel

gapminder %>% 
  filter(year %in% c(1952,1962,1972,1982,1992,2002)) %>%
  filter(continent != 'Oceania') %>%
  ggplot(aes(x= factor(year),
             y= lifeExp, 
             fill = continent)) +
  geom_boxplot() +
  facet_wrap(~continent, ncol = 4) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1),
        axis.title.x= element_blank(),
        legend.position = "none")