r - ggplot2 如何将 x 轴标题放在底部？

Question

我有这个数据框:

      Control     Stress days sd_control  sd_stress
X1 -0.2866667 -0.2833333   X1 0.11846237 0.05773503
X2 -0.2566667 -1.0333333   X2 0.08144528 0.15275252
X3 -0.4766667 -1.4500000   X3 0.09291573 0.10000000
X4 -0.4900000 -1.2766667   X4 0.21517435 0.22501852
X5 -0.4600000 -1.2666667   X5 0.07549834 0.40722639
X6 -0.2633333 -1.0833333   X6 0.12662280 0.10408330
X7 -0.2833333 -1.0333333   X7 0.03511885 0.07767453

根据这些数据我做了这个图:

使用此代码:

ggplot(data = my_mean, 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='ΨMpa\n') +
  scale_y_continuous(limits = c(-2,-0), expand = c(0,0), 
                     breaks = seq(from=0,to=-2.5,by=-0.2)) +
  scale_x_discrete(expand = c(0.07, 0), labels = c(0,7,14,21,27,35,42), 
                   position = "top") +
  ggtitle('Leaf Water Potential\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.title.x.bottom =TRUE),
        axis.text = element_text(family = 'Calibri'),
        legend.text = element_text(family = 'Calibri',face = 'bold'),
        legend.title = element_blank(),
        legend.position = c(0.9, 0.13),
        legend.key = element_rect(fill = NA,color = NA)
  )

请注意我是如何在 scale_x_discrete 中包含 position="top" 参数的，因为我希望轴文本显示在顶部，但我希望轴标题(“DAT ") 回到底部。我想 axis.title.x.bottom 主题函数可以解决问题，但我无法找到如何将它传递给代码以及它需要什么参数。有什么建议吗？

Answer 1

我认为最好的方法是使用没有轴标题的辅助轴 scale_x_continuous(sec.axis = dup_axis(name =''), breaks=c(0,7,14, 21, 28, 35, 42), labels=c('0','7','14', '21', '28', '35', '42'))并切换 x 轴的文本:axis.text.x.bottom = element_blank() .

我用了scale_x_continuous并通过 df$days <- seq(0, 42, 7) 更改日期.如果需要，您也可以关闭底部 x 轴上的刻度。

library(ggplot2)

df <- read.table(text="Control     Stress days sd_control  sd_stress
-0.2866667 -0.2833333   X1 0.11846237 0.05773503
-0.2566667 -1.0333333   X2 0.08144528 0.15275252
-0.4766667 -1.4500000   X3 0.09291573 0.10000000
-0.4900000 -1.2766667   X4 0.21517435 0.22501852
-0.4600000 -1.2666667   X5 0.07549834 0.40722639
-0.2633333 -1.0833333   X6 0.12662280 0.10408330
-0.2833333 -1.0333333   X7 0.03511885 0.07767453", header=T)

df$days <- seq(0,42,7)

ggplot(data = df, 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='ΨMpa\n') +
  scale_y_continuous(limits = c(-2,-0), expand = c(0,0), 
                     breaks = seq(from=0,to=-2.5,by=-0.2)) +
  #scale_x_discrete(expand = c(0.07, 0), labels = c(0,7,14,21,27,35,42)) +
  scale_x_continuous(sec.axis = dup_axis(name =''),
                     breaks=c(0,7,14, 21, 28, 35, 42),
                     labels=c('0','7','14', '21', '28', '35', '42')) +
  ggtitle('Leaf Water Potential\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.x.bottom = element_blank(),
        axis.text.x.bottom = element_blank(),
        #axis.title = element_text(axis.title.x.bottom =TRUE),
        #axis.text = element_text(family = 'Calibri'),
        legend.text = element_text(family = 'Calibri',face = 'bold'),
        legend.title = element_blank(),
        legend.position = c(0.9, 0.13),
        legend.key = element_rect(fill = NA,color = NA)
  )

PS:我把第三根数据线singificance关掉了；不知道从哪里来