ggplot X轴标签超出边界被截断，如何调整绘图区域使其完整显示？

以下是几种实用的调整方案，让右侧X轴标签完整显示：

1. 调整绘图边距 #

在theme()中添加plot.margin参数，给右侧预留额外空间，同时自然缩小绘图区域：

ggplot(test_df, aes(x = Year, y = mydata )) +
  geom_line() +
  labs(y = "S&P 500 EPS / Nominal GDP Normalized") +
  theme_bw()  +         
  theme(axis.title.x = element_text(size = 18, face = "bold"),
        axis.title.y = element_text(size = 18, face = "bold"),
        axis.text.x  = element_text(size = 14),
        axis.text.y  = element_text(size = 14),
        # 边距顺序：上、右、下、左，单位可选lines或cm
        plot.margin = margin(1, 2, 1, 1, "lines")
  )

2. 扩展X轴范围 #

稍微扩大X轴的上限值，给标签留出显示空间：

ggplot(test_df, aes(x = Year, y = mydata )) +
  geom_line() +
  labs(y = "S&P 500 EPS / Nominal GDP Normalized") +
  theme_bw()  +         
  theme(axis.title.x = element_text(size = 18, face = "bold"),
        axis.title.y = element_text(size = 18, face = "bold"),
        axis.text.x  = element_text(size = 14),
        axis.text.y  = element_text(size = 14)
  ) +
  xlim(1929, 2022) # 将X轴上限从2021调整为2022

3. 关闭绘图区域裁剪 #

通过coord_cartesian关闭绘图区域的裁剪限制，允许标签超出绘图边界显示：

ggplot(test_df, aes(x = Year, y = mydata )) +
  geom_line() +
  labs(y = "S&P 500 EPS / Nominal GDP Normalized") +
  theme_bw()  +         
  theme(axis.title.x = element_text(size = 18, face = "bold"),
        axis.title.y = element_text(size = 18, face = "bold"),
        axis.text.x  = element_text(size = 14),
        axis.text.y  = element_text(size = 14)
  ) +
  coord_cartesian(xlim = c(1929, 2021), clip = "off")

内容的提问来源于stack exchange，提问作者Thomas Philips