如何在R中调整x轴尺寸提升可读性？ggplot绘图优化问题

以下是可直接复用的优化方案，按需选择即可： #

方案1：自定义x轴刻度间隔（优先推荐） #

你当前x轴为30分钟间隔的时间值，默认会展示全部48个刻度导致拥挤，可通过scale_x_continuous设置固定间隔展示刻度，比如每2小时展示1个刻度：

electric_cons %>%
  group_by(day_of_week, Hour) %>%
  summarise(AvgUnits = mean(Unit), .groups = "drop") %>%
  ggplot() + 
  geom_bar(aes(x = Hour, y = AvgUnits, fill = AvgUnits), stat = "identity") + 
  # 新增：设置x轴刻度每2小时显示1个，可自行修改breaks的步长
  scale_x_continuous(breaks = seq(0, 23, by = 2), name = "Time") +
  facet_wrap(.~day_of_week) + 
  theme(axis.text.x = element_text(angle=90, vjust=1, hjust=1)) + 
  ggtitle("Average Consumption of electricity during a day", subtitle = "Consumption recorded in every 30 minutes - Weekly ") + 
  ylab("Average units consumed")

方案2：正确实现坐标轴翻转 #

之前使用coord_flip无效大概率是添加位置错误，将其加入图层链即可实现翻转，x轴转为纵向展示后空间更充足：

electric_cons %>%
  group_by(day_of_week, Hour) %>%
  summarise(AvgUnits = mean(Unit), .groups = "drop") %>%
  ggplot() + 
  geom_bar(aes(x = Hour, y = AvgUnits, fill = AvgUnits), stat = "identity") + 
  facet_wrap(.~day_of_week) + 
  # 新增坐标轴翻转
  coord_flip() +
  # 翻转后原x轴变为y轴，调整文本为水平显示更易读
  theme(axis.text.y = element_text(size = 9)) + 
  ggtitle("Average Consumption of electricity during a day", subtitle = "Consumption recorded in every 30 minutes - Weekly ") + 
  xlab("Time") + 
  ylab("Average units consumed")

方案3：调整分面排版增加宽度 #

将分面改为单列纵向排列，每个分面的横向宽度更大，可容纳更多x轴刻度：

electric_cons %>%
  group_by(day_of_week, Hour) %>%
  summarise(AvgUnits = mean(Unit), .groups = "drop") %>%
  ggplot() + 
  geom_bar(aes(x = Hour, y = AvgUnits, fill = AvgUnits), stat = "identity") + 
  # 修改分面为单列排列
  facet_wrap(.~day_of_week, ncol = 1) + 
  theme(axis.text.x = element_text(angle=90, vjust=1, hjust=1)) + 
  ggtitle("Average Consumption of electricity during a day", subtitle = "Consumption recorded in every 30 minutes - Weekly ") + 
  xlab("Time") + 
  ylab("Average units consumed")

额外优化建议 #

如果需要导出高清大图，可在代码末尾加上ggsave语句自定义图片尺寸，进一步放大刻度显示效果：

# 单位为英寸，可按需调整尺寸
ggsave("electric_consumption.png", width = 18, height = 10, dpi = 300)

内容的提问来源于stack exchange，提问作者Thiri Jeyaseelan