我创建了自己的数据框，如何在 ggplot 中创建图例？

Question

我已经创建了自己的data.frame并尝试绘制它。 但是，我只是无法让我的传奇弹出。

我认为在数据的情况下出现了问题。框架部分..但不清楚

有人可以帮我吗？

data <- data.frame(x=c(1, 2, 3, 4, 5),
                y1=c(1, 3, 5, 6, 3),
                y2=c(2, 4, 1, 3, 4))
data

data_plot <- ggplot(data, aes(x), col=group) + geom_smooth(aes(y=y1), color='black') + geom_smooth(aes(y=y2), color='blue') + labs(x="xxx", y="yyy", title="I need help")

data_plot

单击以检查图像

Answer 1

您必须在 aes(...) 中指定颜色，否则它们不会在自动生成的图例中弹出：

library(tidyverse)

data <- data.frame(
  x = c(1, 2, 3, 4, 5),
  y1 = c(1, 3, 5, 6, 3),
  y2 = c(2, 4, 1, 3, 4)
)
data
#>   x y1 y2
#> 1 1  1  2
#> 2 2  3  4
#> 3 3  5  1
#> 4 4  6  3
#> 5 5  3  4

data_plot <- ggplot(data, aes(x), col = group) +
  geom_smooth(aes(y = y1, color = "group 1")) +
  geom_smooth(aes(y = y2, color = "group2")) +
  labs(x = "xxx", y = "yyy", title = "I need help")

data_plot

# long format data frames are better to map group column to color
data %>%
  pivot_longer(matches("y"), values_to = "y") %>%
  ggplot(aes(x, y, color = name)) +
    geom_smooth()

^{由 reprex 包 (v2.0.0)}

Answer 2

您需要在aes()中定义color，例如geom_smooth(aes(y=y1, color='black'))并使用scale_color_identity () 分配颜色。身份尺度的默认值为 guide = "none"。

library(ggplot2)
library(ggthemes)

    ggplot(data, aes(x), col=group) + 
  geom_smooth(aes(y=y1, color='black')) + 
  geom_smooth(aes(y=y2, color='blue')) + 
  scale_color_identity(guide = "legend")+
  labs(x="X-axis", y="Y-axis", title="How to make my legend visible", color="Legend")+
  theme_base()+
  theme(axis.text.x = element_text(hjust = 1, face="bold", size=12, color="black"), 
        axis.title.x = element_text(face="bold", size=16, color="black"),
        axis.text.y = element_text(face="bold", size=12, color="black"),
        axis.title.y = element_text(face="bold", size=16, color="black"),
        legend.text = element_text(color = "black", size = 16,face="bold"),
        legend.title = element_text(face="bold", size=16, color="black"),
        legend.position="top",
        legend.box = "horizontal",
        plot.title = element_text(hjust = 0.5, size=20, face="bold"))

情节：

示例数据：

data <- data.frame(x=c(1, 2, 3, 4, 5),
                   y1=c(1, 3, 5, 6, 3),
                   y2=c(2, 4, 1, 3, 4))
data