18 - Themes.Rmd

---
title: "ggplot2 Elegant Graphics"
author: "Brandon Foltz"
date: "2023-03-16"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
library(tidyverse)
library(ggthemes)
```

```{r}
base <- ggplot(mpg, aes(cty, hwy, color = factor(cyl))) +
  geom_jitter() +
  geom_abline(color = "grey50", linewidth = 2)
base
```

```{r}
labelled <- base +
  labs(
    x = "City mileage per gallon",
    y = "Highway mileage per gallon",
    color = "Cylinders",
    title = "Highway and city mileage are highly correlated") +
  scale_color_brewer(type = "seq", palette = "Spectral"
  )
labelled
```

```{r}
styled <- labelled +
  theme_bw() +
  theme(
    plot.title = element_text(face = "bold", size = 12),
    legend.background = element_rect(fill = "white", linewidth = 4, color = "white"),
    legend.justification = c(0,1),
    legend.position = c(0,1),
    axis.ticks = element_line(color = "grey70", size - 0.2),
    panel.grid.major = element_line(color = "grey70", size = 0.2),
    panel.grid.minor = element_blank()
  )
styled
```

```{r}
df <- data.frame(x = 1:3, y = 1:3)
base <- ggplot(df, aes(x, y)) + geom_point()
base + theme_grey() + ggtitle("theme_grey()")
base + theme_bw() + ggtitle("theme_bw()")
base + theme_linedraw() + ggtitle("theme_linedraw()")
base + theme_light() + ggtitle("theme_light()")
base + theme_dark() + ggtitle("theme_dark()")
base + theme_minimal()  + ggtitle("theme_minimal()")
base + theme_classic() + ggtitle("theme_classic()")
base + theme_void() + ggtitle("theme_void()")
```

GGthemes

```{r}
library(ggthemes)
base + theme_tufte() + ggtitle("theme_tufte()")
base + theme_solarized() + ggtitle("theme_solarized()")
base + theme_excel() + ggtitle("theme_excel()")
```

Modifying Theme Components

```{r}
base_t <- base + labs(title = "This is a ggplot") + xlab(NULL) + ylab(NULL)
base_t + theme(plot.title = element_text(size = 16))
base_t + theme(plot.title = element_text(face = "bold", color = "red"))
base_t + theme(plot.title = element_text(hjust = 1))
```
```{r}
base_t + theme(plot.title = element_text(margin = margin()))
base_t + theme(plot.title = element_text(margin = margin(t = 10, b = 10)))
base_t + theme(axis.title.y = element_text(margin = margin(r = 10)))
```

```{r}
base + theme(panel.grid.major = element_line(color = "black"))
base + theme(panel.grid.major = element_line(size = 2))
base + theme(panel.grid.major = element_line(linetype = "dotted"))
```

```{r}
base + theme(plot.background = element_rect(fill = "grey80", color = NA))
base + theme(plot.background = element_rect(color = "red", size = 2))
base + theme(panel.background = element_rect(fill = "linen"))
```

```{r}
base
last_plot() + theme(panel.grid.minor = element_blank())
last_plot() + theme(panel.grid.major = element_blank())
```

```{r}
last_plot() + theme(panel.background = element_blank())
last_plot() + theme(
  axis.title.x = element_blank(),
  axis.title.y = element_blank()
)
last_plot() + theme(axis.line = element_line(color = "grey50"))
```

```{r}
old_theme <- theme_update(
  plot.background = element_rect(fill = "lightblue3", colour = NA),
  panel.background = element_rect(fill = "lightblue", colour = NA),
  axis.text = element_text(colour = "linen"),
  axis.title = element_text(colour = "linen")
)
base
theme_set(old_theme)
base
```

Theme Elements

When exporting plots to use in other systems, you might want to make the background transparent with fill = NA.

```{r}
base + theme(plot.background = element_rect(color = "grey50", size = 2))
base + theme(
  plot.background = element_rect(color = "grey", size = 2),
  plot.margin = margin(2,2,2,2)
)
base + theme(plot.background = element_rect(fill = "lightblue"))
```

```{r}
df <- data.frame(x = 1:3, y = 1:3)
base <- ggplot(df, aes(x, y)) + geom_point()

# Accentuate the axes
base + theme(axis.line = element_line(colour = "grey50", size = 1))
# Style both x and y axis labels
base + theme(axis.text = element_text(color = "blue", size = 12))
# Useful for long labels
base + theme(axis.text.x = element_text(angle = -90, vjust = 0.5))
```

```{r}
df <- data.frame(
  x = c("label", "a long label", "an even longer label"), 
  y = 1:3
)
base <- ggplot(df, aes(x, y)) + geom_point()
base
base + 
  theme(axis.text.x = element_text(angle = -30, vjust = 1, hjust = 0)) + 
  xlab(NULL) + 
  ylab(NULL)
```

```{r}
df <- data.frame(x = 1:4, y = 1:4, z = rep(c("a", "b"), each = 2))
base <- ggplot(df, aes(x, y, colour = z)) + geom_point()

base + theme(
  legend.background = element_rect(
    fill = "lemonchiffon", 
    colour = "grey50", 
    size = 1
  )
)
base + theme(
  legend.key = element_rect(color = "grey50"),
  legend.key.width = unit(0.9, "cm"),
  legend.key.height = unit(0.75, "cm")
)
base + theme(
  legend.text = element_text(size = 15),
  legend.title = element_text(size = 15, face = "bold")
)
```

```{r}
base <- ggplot(df, aes(x, y)) + geom_point()
# Modify background
base + theme(panel.background = element_rect(fill = "lightblue"))

# Tweak major grid lines
base + theme(
  panel.grid.major = element_line(color = "gray60", size = 0.8)
)
# Just in one direction  
base + theme(
  panel.grid.major.x = element_line(color = "gray60", size = 0.8)
)
```

```{r}
base2 <- base + theme(plot.background = element_rect(colour = "grey50"))
# Wide screen
base2 + theme(aspect.ratio = 9 / 16)
# Long and skiny
base2 + theme(aspect.ratio = 2 / 1)
# Square
base2 + theme(aspect.ratio = 1)
```

```{r}
df <- data.frame(x = 1:4, y = 1:4, z = c("a", "a", "b", "b"))
base_f <- ggplot(df, aes(x, y)) + geom_point() + facet_wrap(~z)

base_f
base_f + theme(panel.spacing = unit(0.5, "in"))
base_f + theme(
  strip.background = element_rect(fill = "grey20", color = "grey80", size = 1),
  strip.text = element_text(colour = "white")
)
#> Warning: The `size` argument of `element_rect()` is deprecated as of ggplot2 3.4.0.
#> ℹ Please use the `linewidth` argument instead.
```