Question

我正在使用ggplot2创建一个图形，其中为不同组绘制的数据在其线型和颜色上都发生变化。我试图更改图例标签，但是，每次尝试更改标签时，我只能针对一种美学（即颜色或线型）更改标签，这会产生两个图例。当两种美学都映射到同一变量时，是否可以更改图例标签？

这是我的工作数据：

# Generate working data
mydat <- structure(list(message_ineq_high_dum = c(0,0,1,1), 
                                    human_message_dum = c(1,0,1,0), 
                                    fit = c(65,60,76,66), 
                                    lwr = c(62,58,74,63), 
                                    upr = c(68,63,79,69), 
                                    var2 = structure(c(1L,1L, 2L, 2L), 
                                                           .Label = c("Low", "High"),
                                                           class = c("ordered","factor")), 
                                    var1 = structure(c(2L, 1L, 2L, 1L), 
                                                                .Label = c("Low","High"), 
                                                                class = c("ordered", "factor"))), 
                               .Names = c("message_ineq_high_dum","human_message_dum", 
                                          "fit", "lwr", "upr", "var2",
                                          "var1"), 
                               class = "data.frame", 
                               row.names = c(NA, -4L))

让我们尝试绘制数据。在此图中，图例标签为“高”和“低”。

# Plot: incorrect legend labels
library(ggplot2)

ggplot2::ggplot(data = mydat,
                aes(x = var2,
                    y = fit,
                    group = var1)) +
  theme_minimal() +
  geom_point(aes(color = var1)) +
  geom_line(aes(color = var1, linetype = var1)) +

  geom_errorbar(aes(ymin = lwr,
                    ymax = upr,
                    width = 0.1,
                    color = var1, 
                    linetype = var1)) +
  labs(x = "var2", y = "var1", color = "var3", linetype = "var3") +
  theme(panel.grid.minor = element_blank()) +
  scale_color_manual(values = c("Low" = "black", "High" = "red")) +
  theme(legend.position="bottom", legend.title = element_blank())

我试图将图例标签从“高”和“低”更改为“ Foo”和“ Bar”，而不进行任何其他更改。我尝试的每种方法都会更改图例标签，同时还要更改（a）图例数量和/或（b）与图例标签相对应的线型/颜色。

Answer 1

您可以使用scale_linetype_manual，但不要忘记设置相同的标签！

library(ggplot2)

ggplot2::ggplot(data = mydat,
                aes(x = var2,
                    y = fit,
                    group = var1)) +
  theme_minimal() +
  geom_point(aes(color = var1)) +
  geom_line(aes(color = var1, linetype = var1)) +

  geom_errorbar(aes(ymin = lwr,
                    ymax = upr,
                    width = 0.1,
                    color = var1, 
                    linetype = var1)) +
  labs(x = "var2", y = "var1", color = "var3", linetype = "var3") +
  theme(panel.grid.minor = element_blank()) +
  scale_colour_manual(labels = c("Foo", "Bar"), values = c("black", "red")) +
  scale_linetype_manual( labels = c("Foo", "Bar"),values = c("solid", "dashed") ) +
  theme(legend.position="bottom", legend.title = element_blank())

更改图例标签而不更改图例标记或数量

1 个答案: