ggplot2 为两个数据系列添加手动图例

Question

我有这个 dataframe：

     Control    Stress days  sd_control  sd_stress
X1 0.9702100 0.9343627   X1 0.001900535 0.07035645
X2 0.9666619 0.8595523   X2 0.014946893 0.04066567
X3 0.9165654 0.7160598   X3 0.072655343 0.07025344
X4 0.9208237 0.6668044   X4 0.050870831 0.08736982
X5 0.8766547 0.7660685   X5 0.073588197 0.04868614
X6 0.9599553 0.7937444   X6 0.041559836 0.05326769
X7 0.9736297 0.8188934   X7 0.003817743 0.06272428

并根据这些数据，我完成了这个 plot：

使用以下代码：

significance <- data.frame(days=c("X2","X3","X4","X6"),value=c(1.02,1.02,1.02,1.02))
ggplot(my_data, aes(x=days,y=Control,group=1)) +
  geom_errorbar(aes(ymax = Control-sd_control, ymin = Control+sd_control),
                width=0.2, size=0.5) +
  geom_errorbar(aes(ymax = Stress-sd_stress, ymin = Stress+sd_stress),
                width=0.2, size=0.5) +
  geom_point(shape=23,color='gray45',fill='gray45',size=4) + 
  geom_line(color='gray45',size=1) +
  geom_point(data=my_data,aes(x=days,y=Stress),size=4,shape=22,fill='gray',color='gray',
             show.legend = TRUE) +
  geom_line(data = my_data, aes(x=days,y=Stress),color='gray',size=1) +
  geom_point(data=significance, aes(x=days,y=value),shape='*',size=6) +
  labs(x='\nDAT',y='RWC\n') +
  scale_y_continuous(labels = percent_format(accuracy = 1),limits = c(0.5,1.04), 
                     expand = c(0,0), breaks = seq(from=0.5,to=1,by=0.05)) +
  scale_x_discrete(expand = c(0.07, 0),labels = c(0,7,14,21,27,35,42)) +
  ggtitle('Relative Water Content\n') +
  theme(panel.border = element_rect(colour = "black", fill=NA, size=0.5),
        panel.background = element_rect(fill = 'white'),
        plot.title = element_text(hjust = 0.5,family = 'Calibri',face='bold'),
        axis.title = element_text(family = 'Calibri',face = 'bold'),
        axis.text = element_text(family = 'Calibri')
        )

我想在 plot 的右下角添加一个图例，描述具有相同形状点的控制和应力处理。 我尝试了几种我在这里找到的方法来设置颜色向量和 scale_colour_manual 属性，但它们都不起作用。 有什么建议吗？

Answer 1

问题是您使用color 、 fill和shape arguments。

• 要获得传奇，您必须在美学上使用 map，即在aes()内部。
• 这样做之后，ggplot 将自动添加 lgends(s)，您可以应用scale_xxx_manual来获得所需的 colors、填充和形状。
• 但是，由于这会导致 3 个图例（无法弄清楚为什么图例的合并失败），我使用guides仅保留其中一个，并guide_legend来设置图例的样式。 尝试这个：

library(ggplot2)
library(scales)

ggplot(my_data, aes(x=days, group=1)) +
  geom_errorbar(aes(ymax = Control-sd_control, ymin = Control+sd_control),
                width=0.2, size=0.5) +
  geom_errorbar(aes(ymax = Stress-sd_stress, ymin = Stress+sd_stress),
                width=0.2, size=0.5) +
  geom_point(aes(y=Control, color = "Control", fill = "Control", shape = "Control"), size=4) + 
  geom_line(aes(y=Control, color = "Control"),size=1) +
  geom_point(aes(y=Stress, color = "Stress", fill = "Stress", shape = "Stress"), size=4) +
  geom_line(aes(y=Stress, color = "Stress"), size=1) +
  geom_point(data=significance, aes(y=value),shape='*',size=6) +
  scale_color_manual(values = c("Control" = 'gray45', "Stress" = 'gray') ) +
  scale_fill_manual(values = c("Control" = 'gray45', "Stress" = 'gray') ) +
  scale_shape_manual(values = c("Control" = 23, "Stress" = 22)) +
  guides(shape = FALSE, fill = FALSE, 
         color = guide_legend(override.aes = list(shape =  c("Control" = 23, "Stress" = 22),
                                                  fill = c("Control" = 'gray45', "Stress" = 'gray')))) +
  labs(x='\nDAT',y='RWC\n') +
  scale_y_continuous(labels = percent_format(accuracy = 1),limits = c(0.5,1.04), 
                     expand = c(0,0), breaks = seq(from=0.5,to=1,by=0.05)) +
  scale_x_discrete(expand = c(0.07, 0), labels = c(0,7,14,21,27,35,42)) +
  ggtitle('Relative Water Content\n') +
  theme(panel.border = element_rect(colour = "black", fill=NA, size=0.5),
        panel.background = element_rect(fill = 'white'),
        plot.title = element_text(hjust = 0.5,family = 'Calibri',face='bold'),
        axis.title = element_text(family = 'Calibri',face = 'bold'),
        axis.text = element_text(family = 'Calibri')
  )