Some aspects of ggplot2 - Titanic Version

---

---

```r
library(tidyverse)
library(knitr)
library(ggplot2)
df <- read_csv('../data/titanic.csv')
df <- df %>% 
  mutate(Survived = as.character(Survived),
         Pclass = as.character(Pclass))
```

---

```r
df %>% ggplot()+ 
  geom_point(mapping=aes(x=Age, y=Fare))
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-2-1.png)

---

```r
df %>% ggplot()+ 
  geom_point(mapping=aes(x=Age, y=Fare))+
  geom_smooth(mapping=aes(x=Age, y=Fare))
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-3-1.png)
---
class: inverse, middle, center
# Facets
---

```r
df %>% ggplot()+ 
  geom_point(mapping=aes(x=Age, y=Fare))+
  facet_wrap(~Pclass)
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-4-1.png)

---

```r
df %>% ggplot()+ 
  geom_point(mapping=aes(x=Age, y=Fare))+
  facet_wrap(~Pclass+Sex)
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-5-1.png)

---
class: inverse, middle, center
# Position adjustments
---

```r
df %>% ggplot()+ 
  geom_bar(mapping=aes(x=Sex, fill=Survived), 
           position = 'dodge')
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-6-1.png)
---

```r
df %>% ggplot()+ 
  geom_bar(mapping=aes(x=Sex, fill=Survived), 
           position = 'fill')
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-7-1.png)
---
class: inverse, middle, center

# geom_bar vs. geom_col
---
**geom_bar for one categorical variable**

```r
df %>% ggplot()+ 
  geom_bar(mapping=aes(x=Pclass))
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-8-1.png)

---
**geom_col for one categorical variable and one continuous variable**

```r
df %>% group_by(Pclass) %>% 
  summarise(average_age=mean(Age, na.rm=TRUE)) %>% 
  ggplot()+ 
  geom_col(mapping=aes(x=Pclass, y=average_age))
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-9-1.png)

---
class: inverse, middle, center
# Labels/Title

---

```r
df %>% 
  group_by(Pclass, Sex) %>% 
  summarise(average_age=mean(Age, na.rm=TRUE)) %>% 
  ggplot()+ 
  geom_col(mapping=aes(x=Pclass, 
                       y=average_age, 
                       fill=Sex), 
           position = 'dodge')+
  labs(x='Class in the Titanic', 
       y = 'Average Age', 
       fill='Gender', 
       title = 'Average Age of Passenger by Class and Gender', 
       caption = 'The higher the class, the younger the passengers.')
```

---

![](7_viz_titanic_files/figure-html/unnamed-chunk-11-1.png)

---
class: inverse, middle, center

# Change Themes

---

```r
df %>% ggplot()+ 
    geom_bar(mapping=aes(x=Sex, fill=Survived))
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-12-1.png)

---

```r
df %>% ggplot()+ 
    geom_bar(mapping=aes(x=Sex, fill=Survived))+
  theme_dark()
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-13-1.png)

---

```r
df %>% ggplot()+ 
    geom_bar(mapping=aes(x=Sex, fill=Survived))+
  theme_linedraw()
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-14-1.png)

---
# More Themes

- https://ggplot2.tidyverse.org/reference/ggtheme.html

---
**`ggthemes` package**

```r
df %>% ggplot()+ 
  geom_point(mapping=aes(x=Age, y=Fare, color=Survived))+
  facet_wrap(~Sex)
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-15-1.png)

---
**`ggthemes` package**

```r
library(ggthemes)
df %>% ggplot()+ 
  geom_point(mapping=aes(x=Age, y=Fare, color=Survived))+
  facet_wrap(~Sex)+
  scale_color_stata()
```

![](7_viz_titanic_files/figure-html/unnamed-chunk-16-1.png)

---
**Save plots**

```r
gg <- df %>% ggplot()+ 
    geom_bar(mapping=aes(x=Sex, fill=Survived))+
  theme_dark()
ggsave(filename = 'abc.png', plot = gg)
```

---
class: inverse, middle, center
# dplyr + ggplot

---
**filter + ggplot**

```r
df %>% 
    filter(Age>=13, Age<=19) %>% 
    ggplot()+
    geom_bar(mapping=aes(x=Sex, fill=Survived))
```

---
**group_by + summarise + geom_col**

```r
df %>% 
  group_by(Survived, Pclass) %>% 
  summarise(mean_fare = Fare) %>% 
  ggplot()+
  geom_col(aes(x=Pclass, y=mean_fare, fill=Survived), position = 'dodge')
```