指定在wrap_plots中保留哪个图例（拼凑而成）

Question

我希望将不同函数生成的多个图表组合到一个显示中。具体来说，我只想保留第一个图表的图例。

这是问题的最小版本：

library(ggplot2)
library(patchwork)

plot_histogram <- function() {
    plot_data <- ggplot(mtcars, aes(x = mpg, fill = factor(am))) +
        geom_histogram(binwidth = 2, color = "black") +
        labs(title = "Histo",
             x = "Miles/gallon",
             y = "nb cars",
             fill = "Transmission") +
        scale_fill_manual(values = c("skyblue", "salmon"), labels = c("Auto", "Man")) +
        theme_minimal() +
        theme(legend.position = "bottom")
    
    return(plot_data)
}

plot_scatter <- function() {
    plot_data <- ggplot(mtcars, aes(x = mpg, y = wt, color = factor(cyl))) +
        geom_point(size = 3) +
        labs(title = "Scatterplot",
             x = "Miles/gallon",
             y = "weight",
             color = "Cyl") +
        theme_minimal() +
        theme(legend.position = "bottom")
    
    return(plot_data)
}

scatter_plot_left <- plot_scatter()
scatter_plot_right <- plot_scatter()
histogram_plot <- plot_histogram()

combined_plots <- wrap_plots(scatter_plot_left + scatter_plot_right,
                             histogram_plot,
                             nrow = 1,
                             widths = c(3, 1)) +
    plot_layout(guides = 'collect') &
    theme(legend.position = "bottom")

combined_plots

组合图

有没有办法只保留散点图的图例？

从现在开始，我发现的最好的“解决方案”是用

guides = 'collect'

包裹前两个图表，然后用另一个图表包裹它而不保留图例。

这并不是一个真正的解决方案，因为图例不居中，您必须每次都调整图形的大小，这在自动生产过程中并不好。

提前谢谢您。

Answer 1

你可以像这样在函数中将

legend.position

作为参数吗？

library(ggplot2)
library(patchwork)

plot_histogram <- function(x) {
  ggplot(mtcars, aes(x = mpg, fill = factor(am))) +
    geom_histogram(binwidth = 2, color = "black") +
    labs(
      title = "Histo",
      x = "Miles/gallon",
      y = "nb cars",
      fill = "Transmission"
    ) +
    scale_fill_manual(values = c("skyblue", "salmon"), labels = c("Auto", "Man")) +
    theme_minimal() +
    theme(legend.position = x)
}

plot_scatter <- function(x) {
  ggplot(mtcars, aes(x = mpg, y = wt, color = factor(cyl))) +
    geom_point(size = 3) +
    labs(
      title = "Scatterplot",
      x = "Miles/gallon",
      y = "weight",
      color = "Cyl"
    ) +
    theme_minimal() +
    theme(legend.position = x)
}

scatter_plot_left <- plot_scatter("none")
scatter_plot_right <- plot_scatter("bottom")
histogram_plot <- plot_histogram("none")

wrap_plots(scatter_plot_left + scatter_plot_right,
  histogram_plot,
  nrow = 1,
  widths = c(3, 1)
)

^{创建于 2024-05-03，使用 reprex v2.1.0}