僅使用ggplot2繪制時間

Question

我有一個這樣的數據框：

 head(yy)
    Team       Date STime ETime
1    A 2012-03-06 07:03 10:13
2    A 2012-03-06 07:03 10:13
3    A 2012-03-06 07:03 10:13
4    A 2012-03-06 07:03 10:13
5    A 2012-03-06 07:03 10:13
6    A 2012-03-06 07:03 10:13

dput（YY）

dput(yy)
structure(list(Team = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "A", class = "factor"), 
Date = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "2012-03-06", class = "factor"), 
STime = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "07:03", class = "factor"), 
ETime = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "10:13", class = "factor")), .Names = c("Team", 
"Date", "STime", "ETime"), class = "data.frame", row.names = c(NA, 
-50L))

我喜歡在2小時內從00:00 23:59看到y軸，並且能夠在STime值上繪制一條紅線。

我有這樣的事情，但它看起來不正確：

ggplot(yy, aes(Date, ETime, group="Team")) + geom_jitter(size=0.05) + facet_wrap( ~ Team) + geom_hline(yintercept=yy$Stime, colour="red", size=2)

你會如何在ggplot2中做到這一點？ 有人可以給我指點/讓我朝着正確的方向前進嗎？

問候，

Answer 1

您必須將時間格式化為實際時間。 現在它們是因素（用str(yy)檢查數據框）。 繪制ETime時，將單個時間繪制為1並標記為“10:13”。 因此，下面的解決方案首先將字符串“10:13”轉換為時間（ strptime ），然后將其轉換為POSIXct ，或者自原點（ POSIXct日）以來的秒數。

library(ggplot2); library(scales)

#Convert date string into POSIXct format
yy$STime <- as.POSIXct(strptime(yy$STime, format = "%H:%M", tz = "UTC"))
yy$ETime <- as.POSIXct(strptime(yy$ETime, format = "%H:%M", tz = "UTC"))

#Define y-axis limits
lims <- as.POSIXct(strptime(c("0:00","23:59"), format = "%H:%M", tz= "UTC"))    

ggplot(yy, aes(Date, ETime, group="Team")) + geom_jitter(size=1) + facet_wrap( ~ Team) + 
  geom_hline(data = yy, aes(yintercept= as.numeric(STime)), colour="red", size=2) + 
  scale_y_datetime(limits =lims, breaks=date_breaks("2 hour"),
                   labels=date_format("%H:%M", tz = "UTC") )

關於geom_line到日期軸的注意事項。

也要注意你的時區。 否則R / ggplot將根據您當地的時區格式化。