将标签（即“ A”，“ B”）添加到多面包装ggplot

Question

Figure with desired locations of "A" and "B"

我想将“ A”和“ B”标签放置在刻度轴标签上方的左上方。我还想删除在左下方的“ NA”区域中绘制的网格背景。编写两个图的代码：

Matrix([[17.0],[23.0]])

Answer 1

library(cowplot)
twoplots <- plot_grid(Aplot,Bplot,labels="AUTO",ncol=1,align='v',axis='r',label_x=0,hjust=0,label_size=10,rel_heights = c(5,1))