ggplot绘制y轴时间值：解决分类时间轴排序异常问题

我有一个名为data_clean的数据集，参与者10天内完成多轮survey。其中distress是分类变量，存储格式为「时:分」（如1:00、23:15）。用ggplot绘制Spaghetti图时，y轴时间按字母顺序排列，而非时间顺序，推测是因为变量为分类类型。

初始绘图代码 #

slopes_np<-ggplot(data = data_clean, aes(x=survey,y=distress, group=id, color=id))+
  facet_wrap(~PP_rec)+
  geom_smooth(method='lm', se=FALSE, size=0.5)+ 
  xlab("Survey")+ylab("Distress")+
  theme(legend.position = "none")
slopes_np

# 整体组的平滑线
smooth_nopoints <- slopes_np + stat_smooth(aes(group = 1), method = "lm", se = FALSE, colour="black", size=1) 
smooth_nopoints

尝试的无效方法（引入无关日期） #

用as.POSIXct转换时间变量后，图表出现无关日期，不符合需求：

data_clean$distress_time <- as.POSIXct(data_clean$distress, format="%H:%M")
class(data_clean$distress_time)

theme_set(theme_bw(base_size = 7, base_family = ""))

slopes_np<-ggplot(data = data_clean, aes(x=survey,y=distress_time, group=id, color=id))+
  facet_wrap(~PP_rec)+
  geom_smooth(method='lm', se=FALSE, size=0.5)+
  xlab("Survey")+ylab("Distress")+
  theme(legend.position = "none")
slopes_np

# 整体组的平滑线
smooth_nopoints <- slopes_np + stat_smooth(aes(group = 1), method = "lm", se = FALSE, colour="black", size=1) 
smooth_nopoints

需求：y轴仅显示按时间顺序排列的「时:分」格式（如0:00、1:00…23:00）。

示例数据 #

structure(list(id = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L), levels = c("400", "401", "402", "403", "404", "405", "406", "407", "408", "409", "411", "412", "413", "414", "415", "550", "551", "552", "553", "554", "555", "558", "559", "560", "561", "563", "565", "566", 
"567", "568", "569", "570", "571", "572", "573", "574", "575", 
"576", "577", "578", "580", "590", "591"), class = "factor"), 
distress = c("23:45", "23:30", "23:30", "23:45", "23:30", 
    "22:30", "23:30", "21:30", "23:45", "22:45", "0:00", "1:00", 
    "6:15", "0:00", "1:00", "0:00", "2:00", "2:00", "2:00", "1:45"
    ), survey = c(1, 4, 6, 9, 11, 1, 3, 5, 8, 11, 1, 4, 7, 9, 
    12, 1, 4, 7, 10, 12)))

# PP_rec表示事件发生的前后

推荐使用hms包处理时间，它专门用于存储时分秒类型，不会引入日期，且ggplot能自动识别时间顺序。

方法：使用hms类型变量自定义y轴格式 #

library(ggplot2)
library(hms)

# 将distress转换为hms类型（仅含时分秒，无日期）
data_clean$distress_hms <- as_hms(data_clean$distress)

# 绘制Spaghetti图
slopes_np <- ggplot(data = data_clean, aes(x = survey, y = distress_hms, group = id, color = id)) +
  facet_wrap(~PP_rec) +
  geom_smooth(method = 'lm', se = FALSE, size = 0.5) +
  # 自定义y轴显示格式为「时:分」
  scale_y_time(format = "%H:%M") +
  xlab("Survey") +
  ylab("Distress") +
  theme(legend.position = "none")

# 添加整体组的平滑线
smooth_nopoints <- slopes_np + 
  stat_smooth(aes(group = 1), method = "lm", se = FALSE, colour = "black", size = 1) 

# 输出图表
smooth_nopoints

可选调整 #

如果需要y轴只显示整点刻度（如0:00、1:00…23:00），可以修改scale_y_time参数：

scale_y_time(
  format = "%H:%M",
  breaks = seq(hms(00, 00, 00), hms(23, 00, 00), by = "hour")
)

内容的提问来源于stack exchange，提问作者o.y_80