随机选择ggtheme

Question

我想绘制一个随机主题的ggplot(事实上,我想绘制许多情节,每个情节都有不同的主题).考虑以下可重现的示例:

# Exmple data
df <- data.frame(x = 1:10, y = 1:10)

# Select theme randomly
random_theme <<- sample(c("theme_gray", "theme_bw", "theme_light", "theme_dark", "theme_minimal", "theme_classic"), 1)

# Draw ggplot
ggplot(df, aes(x, y)) +
  geom_line() +
  random_theme            # This line does not work

问题:如何随机选择ggtheme？

Answer 1

来自函数的示例而不是函数的名称.此外,样本在从比标量更复杂的任何内容进行采样时返回一个列表,因此您需要第一个列表元素.例如:

> sample(c(sqrt, sqrt),2)
[[1]]
function (x)  .Primitive("sqrt")

[[2]]
function (x)  .Primitive("sqrt")

所以得到一个随机主题函数:

random_theme <- sample(c(theme_gray, theme_bw, theme_light, theme_dark, theme_minimal, theme_classic), 1)[[1]]

在你绘图时调用它:

ggplot(df, aes(x, y)) +geom_line() + random_theme()

random_theme重新采样并重新绘制以进行更新.

此外,你可能不需要<<-我想的是一个宿醉,拼命想让一些东西工作......

Answer 2

你可以这样做match.fun():

random_theme = match.fun(sample(c("theme_gray", "theme_bw", "theme_light", "theme_dark", "theme_minimal", "theme_classic"), 1))

ggplot(df, aes(x, y)) +
 geom_line() +
 random_theme()

Answer 3

由于您random_theme是一个character向量，因此您可以使用eval然后parse来解析您的主题。

library(tidyverse)

ggplot(df, aes(x, y)) +
  geom_line() +
  eval(parse(text = paste0(random_theme, "()")))

或者更直接地说：

ggplot(df, aes(x, y)) +
  geom_line() +
  eval(parse(text = paste0(sample(c("theme_gray",
                                    "theme_bw", 
                                    "theme_light", 
                                    "theme_dark", 
                                    "theme_minimal", 
                                    "theme_classic"), 1)  , "()")))