Add multiple horizontal lines in a boxplot
问题 I know that I can add a horizontal line to a boxplot using a command like abline(h=3) When there are multiple boxplots in a single panel, can I add different horizontal lines for each single boxplot? In the above plot, I would like to add lines 'y=1.2' for 1, 'y=1.5' for 2, and 'y=2.1' for 3. 回答1: I am not sure that I understand exactly, what you want, but it might be this: add a line for each boxplot that covers the same x-axis range as the boxplot. The width of the boxes is controlled by