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ggplot2 主题

图形外观定制

Tidyverse 篇

这一章我们一起学习ggplot2中的theme elements 语法，感谢Henry Wang提供了很好的思路。如果需要详细了解，可以参考Hadley Wickham最新版的《ggplot2: Elegant Graphics for Data Analysis》，最推荐的是ggplot2官方文档

R 
theme(element_name = element_function())

这里element_function()有四个

R 
element_text()
element_line()
element_rect()
element_blank()

望文生义吧，内置元素函数有四个基础类型：

  • element_text(), 文本，一般用于控制标签和标题的字体风格
  • element_line(), 线条，一般用于控制线条或线段的颜色或线条类型
  • element_rect(), 矩形区域，一般用于控制背景矩形的颜色或者边界线条类型
  • element_blank() , 空白，就是不分配相应的绘图空间，即删去这个地方的绘图元素。

每个元素函数都有一系列控制外观的参数，下面我们通过具体的案例来一一介绍吧。

R 
library(tidyverse)

还是用让人生厌的ggplot2::mpg数据包吧，具体介绍请见 章。

R 
glimpse(mpg)

稍微做点数据整理

R 
df <- mpg %>% 
  as_tibble() %>% 
  filter(class != "2seater", manufacturer %in% c("toyota", "volkswagen"))
df

我相信这种图你们已经会画了吧

R 
df %>%
  ggplot(aes(x = displ, y = hwy, color = factor(cyl))) +
  geom_point() +
  facet_grid(vars(manufacturer), vars(class)) +
  ggtitle("This is my title") +
  labs(x = "x_displ", y = "y_hwy")

想让这张图，符合你的想法？如何控制呢？come on

图表整体元素

图表整体元素包括:

描述主题元素类型
整个图形背景plot.backgroundelement_rect()
图形标题plot.titleelement_text()
图形边距plot.marginmargin()
R 
df %>%
  ggplot(aes(x = displ, y = hwy, color = factor(cyl))) +
  geom_point() +
  facet_grid(vars(manufacturer), vars(class)) +
  ggtitle("This is my title") +
  labs(x = "x_displ", y = "y_hwy") +
  theme(
    plot.background = element_rect(fill = "orange", color = "black", size = 10),
    plot.title = element_text(hjust = 1, color = "red", face = "italic"),
    plot.margin = margin(t = 20, r = 20, b = 20, l = 20, unit = "pt")
  )

坐标轴元素

坐标轴元素包括:

描述主题元素类型
坐标轴刻度axis.tickselement_line()
坐标轴标题axis.titleelement_text()
坐标轴标签axis.textelement_text()
直线和坐标轴axis.lineelement_line()
R 
df %>%
  ggplot(aes(x = displ, y = hwy, color = factor(cyl))) +
  geom_point() +
  facet_grid(vars(manufacturer), vars(class)) +
  ggtitle("This is my title") +
  labs(x = "x_displ", y = "y_hwy") +
  theme(
    axis.line = element_line(color = "orange", size = 2),
    axis.title = element_text(color = "red", face = "italic"),
    axis.ticks = element_line(color = "purple", size = 3),
    axis.text = element_text(color = "blue"),
    axis.text.x = element_text(angle = 45, hjust = 1)
  )

面板元素

面板元素包括:

描述主题元素类型
面板背景panel.backgroundelement_rect()
面板网格线panel.gridelement_line()
面板边界panel.borderelement_rect()
R 
df %>%
  ggplot(aes(x = displ, y = hwy, color = factor(cyl))) +
  geom_point() +
  facet_grid(vars(manufacturer), vars(class)) +
  ggtitle("This is my title") +
  labs(x = "x_displ", y = "y_hwy") +
  theme(
    panel.background = element_rect(fill = "orange", color = "red"),
    panel.grid = element_line(color = "grey80", size = 0.5)
  )

或者

R 
df %>%
  ggplot(aes(x = displ, y = hwy, color = factor(cyl))) +
  geom_point() +
  facet_grid(vars(manufacturer), vars(class)) +
  ggtitle("This is my title") +
  labs(x = "x_displ", y = "y_hwy") +
  theme(
    panel.background = element_rect(fill = "orange"),
    panel.grid = element_line(color = "grey80", size = 0.5),
    panel.border = element_rect(color = "red", fill = NA)
  )

图例元素

图例元素包括:

描述主题元素类型
图例背景legend.backgroundelement_rect()
图例符号legend.keyelement_rect()
图例标签legend.textelement_text()
图例标题legend.titleelement_text()
图例边距legend.marginmargin
图例位置legend.postion"top", "bottom", "left", "right"
R 
df %>%
  ggplot(aes(x = displ, y = hwy, color = factor(cyl))) +
  geom_point() +
  facet_grid(vars(manufacturer), vars(class)) +
  ggtitle("This is my title") +
  labs(x = "x_displ", y = "y_hwy") +
  theme(
    legend.background = element_rect(fill = "orange"),
    legend.title = element_text(color = "blue", size = 10),
    legend.key = element_rect(fill = "grey80"),
    legend.text = element_text(color = "red"),
    legend.margin = margin(t = 20, r = 20, b = 20, l = 20, unit = "pt"),
    legend.position = "bottom"
  )

分面元素

分面元素包括:

描述主题元素类型
分面标签背景strip.backgroundelement_rect()
条状文本strip.textelement_text()
分面间隔panel.spacingunit
R 
df %>%
  ggplot(aes(x = displ, y = hwy, color = factor(cyl))) +
  geom_point() +
  facet_grid(vars(manufacturer), vars(class)) +
  ggtitle("This is my title") +
  labs(x = "x_displ", y = "y_hwy") +
  theme(
    strip.background = element_rect(fill = "orange"),
    strip.text = element_text(color = "red"),
    panel.spacing = unit(0.3, "inch") 
    # strip.switch.pad.grid =
  )

案例

R 
diamonds %>%
  ggplot(aes(carat, price)) +
  geom_hex() +
  labs(title = "Diamond") +
  theme(
    axis.title.x = element_text(
      size = 30,
      color = "red",
      face = "bold",
      angle = 10
    ),
    legend.title = element_text(
      size = 25,
      color = "#ff6361",
      margin = margin(b = 5)
    ),
    plot.title = element_text(
      size = 35,
      face = "bold",
      color = "blue"
    )
  )

你肯定不会觉得这图好看。

R 
library(palmerpenguins)
penguins %>%
  ggplot(aes(bill_length_mm, bill_depth_mm)) +
  geom_point() +
  theme(
    axis.line.y = element_line(
      color = "black",
      size = 1.2,
      arrow = grid::arrow()
    ),
    axis.line.x = element_line(
      linetype = "dashed",
      color = "brown",
      size = 1.2
    ),
    axis.ticks = element_line(color = "red", size = 1.1),
    axis.ticks.length = unit(3, "mm"),
    panel.grid.major = element_line(
      color = "blue",
      size = 1.2
    ),
    panel.grid.minor = element_line(
      color = "#58508d",
      size = 1.2,
      linetype = "dotted"
    )
  )
R 
penguins %>%
  ggplot(aes(bill_length_mm, bill_depth_mm)) +
  geom_point(aes(color = species)) +
  theme(
    legend.background = element_rect(
      fill = "#fff6c2",
      color = "black",
      linetype = "dashed"
    ),
    legend.key = element_rect(fill = "grey", color = "brown"),
    panel.background = element_rect(
      fill = "#005F59",
      color = "red", size = 3
    ),
    panel.border = element_rect(
      color = "black",
      fill = "transparent",
      linetype = "dashed", size = 3
    ),
    plot.background = element_rect(
      fill = "#a1dce9",
      color = "black",
      size = 1.3
    ),
    legend.position = "bottom"
  )

小结

图片

主题风格

当然可以使用自带的主题风格

R 
penguins %>% 
    ggplot(aes(x = bill_depth_mm, y = bill_length_mm)) +
    geom_point() +
    theme_minimal()
R 
penguins %>% 
  ggplot(aes(x = bill_depth_mm, y = bill_length_mm)) +
  geom_point() +
  theme_bw() +
  theme(text = element_text(family = "serif", size = 20),
        panel.grid = element_blank()
        )

当然，ggthemes宏包也提供了很多优秀的主题风格

R 
library(ggthemes)
penguins %>% 
    ggplot(aes(x = bill_depth_mm, y = bill_length_mm)) +
    geom_point() +
    ggthemes::theme_economist()
R 
gapdata <- read_csv("./demo_data/gapminder.csv")
gapdata %>%
  ggplot(aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  geom_smooth(lwd = 3, se = FALSE, method = "lm") +
  theme_grey() # the default
R 
gapdata %>%
  ggplot(aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  geom_smooth(lwd = 3, se = FALSE, method = "lm") +
  theme_bw()
R 
gapdata %>%
  ggplot(aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  geom_smooth(lwd = 3, se = FALSE, method = "lm") +
  ggthemes::theme_calc() +
  ggtitle("ggthemes::theme_calc()")
R 
gapdata %>%
  ggplot(aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  geom_smooth(lwd = 3, se = FALSE, method = "lm") +
  ggthemes::theme_economist() +
  ggtitle("ggthemes::theme_economist()")
R 
gapdata %>%
  ggplot(aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  geom_smooth(lwd = 3, se = FALSE, method = "lm") +
  ggthemes::theme_economist_white() +
  ggtitle("ggthemes::theme_economist_white()")
R 
gapdata %>%
  ggplot(aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  geom_smooth(lwd = 3, se = FALSE, method = "lm") +
  ggthemes::theme_few() +
  ggtitle("ggthemes::theme_few()")
R 
gapdata %>%
  ggplot(aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  geom_smooth(lwd = 3, se = FALSE, method = "lm") +
  ggthemes::theme_gdocs() +
  ggtitle("ggthemes::theme_gdocs()")
R 
gapdata %>%
  ggplot(aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  geom_smooth(lwd = 3, se = FALSE, method = "lm") +
  ggthemes::theme_tufte() +
  ggtitle("ggthemes::theme_tufte()")
R 
gapdata %>%
  ggplot(aes(x = gdpPercap, y = lifeExp, color = continent)) +
  geom_point() +
  geom_smooth(lwd = 3, se = FALSE, method = "lm") +
  ggthemes::theme_wsj() +
  ggtitle("ggthemes::theme_wsj()")

提问

  • ggplot2中 plot 与 panel 有区别？
  • 假定数据是这样
R 
library(tidyverse)
set.seed(12)

d1 <- data.frame(x = rnorm(50, 10, 2), type = "Island #1")
d2 <- data.frame(x = rnorm(50, 18, 1.2), type = "Island #2")

dd <- bind_rows(d1, d2) %>%
  set_names(c("Height", "Location"))

head(dd)

你画图后，交给老板看

R 
dd %>%
  ggplot(aes(x = Height, fill = Location)) +
  geom_histogram(binwidth = 1, color = "white") +
  scale_fill_manual(values = c("green3", "turquoise3"))

然而，老板有点不满意，希望你要这样改 !图片

请用前后两章学到的内容让老板满意吧

R 
# remove the objects
# rm(list=ls())
rm(d1, d2, dd, df)
R 
pacman::p_unload(pacman::p_loaded(), character.only = TRUE)