intRo: Data visualisation with R

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# intRo: Data visualisation with R
## 03 — Plot with ggplot2
### Stefano Coretta

---

# Visualise data

![](../img/data-viz.png)

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# Graphic systems

- Base R.

- lattice.

- ggplot2.

- more...

---

# Base R plotting function

```r
x <- 1:10
y <- x^3

plot(x, y)
```

---

# Base R plotting function

![](index_files/figure-html/scatter-plot-1.png)

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# Base R plotting function

```r
x <- seq(1, 10, by = 0.01)
y <- x^3

plot(x, y, type = "l", col = "purple", lwd = 3, lty = "dashed")
```

---

# Base R plotting function

![](index_files/figure-html/line-plot-1.png)

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# Packages to the rescue

<br>

- The R **library** contains the installed packages.

- Base R.

- Extra packages.

- Install extra packages with `install.packages()`.

.bg-washed-blue.b--dark-blue.ba.bw2.br3.shadow-5.ph4.mt5[

Run this in the console:

```r
install.packages("fortunes")
```

]

---

# Packages to the rescue

To use a package installed in the library, you `attach` the package with `library()`.

.bg-washed-blue.b--dark-blue.ba.bw2.br3.shadow-5.ph4.mt5[

Run this in the console:

```r
library(fortunes)
```

]

---

# Packages to the rescue

Now you can use the functions provided by the attached package

.bg-washed-blue.b--dark-blue.ba.bw2.br3.shadow-5.ph4.mt5[

Run this in the console:

```r
fortune()
```

```
## 
## John Fox: I've never understood why it's legal to change the built-in global
## "constants" in R, including T and F. That just seems to me to set a trap for users.
## Why not treat these as reserved symbols, like TRUE, Inf, etc.?
## Rolf Turner: I rather enjoy being able to set pi <- 3.
##    -- John Fox and Rolf Turner
##       R-help (June 2013)
```

]

---

# Do you sleep like a giraffe or a brown bat?

```r
ggplot(
  data = msleep,
  mapping = aes(x = sleep_total, y = sleep_rem)
) +
  geom_point()
```

---

# Do you sleep like a giraffe or a brown bat?

---

# Do you sleep like a giraffe or a brown bat?

```r
library(ggrepel)

ggplot(
  data = msleep,
  mapping = aes(x = sleep_total, y = sleep_rem, label = name)
) +
  geom_point() +
  geom_label_repel()
```

---

# Do you sleep like a giraffe or a brown bat?

---

# Social media users 2008-2019

```r
social %>%
  filter(platform %in% c(
    "Facebook", "Twitter", "TikTok", "Instagram", "YouTube"
    )
  ) %>%
  ggplot(aes(year, users, colour = platform)) +
  geom_line() +
  geom_point()
```

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# Social media users 2008-2019

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# Language endangerment

```r
endangered %>%
  ggplot(aes(status, fill = status)) +
  geom_bar() +
  scale_fill_brewer(palette = "Reds")
```

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# Language endangerment

---

# Hogwarts houses and astrological elements

```r
harry_potter %>%
  ggplot(aes(element, fill = house)) +
  geom_bar(position = "dodge") +
  scale_fill_manual(
    values = c("#76040a", "#f29e02", "#0121a2", "#1d492c")
  )
```

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# Hogwarts houses and astrological elements

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# Student/teacher ratio

```r
df_ratios %>%
  mutate(
    region = fct_reorder(region, -student_ratio_region)
  ) %>%
  ggplot(
    aes(x = region, y = student_ratio, color = region)
  ) +
  geom_jitter(size = 4, alpha = 0.6, width = 0.2) +
  coord_flip() +
  labs(
    y = "Student to teacher ratio",
    x = element_blank()
  ) +
  theme(legend.position = "none")
```

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# Student/teacher ratio

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# Do you decline invitations?

```r
ggplot(data = fly) +
  geom_mosaic(aes(x = product(rude_to_recline), fill = do_you_recline)) +
  labs(x = "Is it rude to decline?", y = "Do you decline?") +
  theme_mosaic() +
  theme(legend.position = "none")
```

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# Do you decline invitations?

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.f1[TUTORIAL]