我有两个大型数据集,如下所示:
df1=data.frame(subject = c(rep(1, 12), rep(2, 10)), day =c(1,1,1,1,1,2,3,15,15,15,15,19,1,1,1,1,2,3,15,15,15,15),stime=c('4/16/2012 6:25','4/16/2012 7:01','4/16/2012 17:22','4/16/2012 17:45','4/16/2012 18:13','4/18/2012 6:50','4/19/2012 6:55','5/1/2012 6:28','5/1/2012 7:00','5/1/2012 16:28','5/1/2012 17:00','5/5/2012 17:00','4/23/2012 5:56','4/23/2012 6:30','4/23/2012 16:55','4/23/2012 17:20','4/25/2012 6:32','4/26/2012 6:28','5/8/2012 5:54','5/8/2012 6:30','5/8/2012 15:55','5/8/2012 16:30'))
df2=data.frame(subject = c(rep(1, 10), rep(2, 10)), day=c(1,1,2,2,3,3,9,9,15,15,1,1,2,2,3,3,9,9,15,15),dtime=c('4/16/2012 6:15','4/16/2012 15:16','4/18/2012 7:15','4/18/2012 21:45','4/19/2012 7:05','4/19/2012 23:17','4/28/2012 7:15','4/28/2012 21:12','5/1/2012 7:15','5/1/2012 15:15','4/23/2012 6:45','4/23/2012 16:45','4/25/2012 6:45','4/25/2012 21:30','4/26/2012 6:45','4/26/2012 22:00','5/2/2012 7:00','5/2/2012 22:00','5/8/2012 6:45','5/8/2012 15:45'))
。
在DF2中,"dtime"每天包含每个主题的两个时间点。我想在 df1 中使用每天每个子子的时间点(即。'stime')减去DF2中每天每个子的第二个时间点,如果结果为正,则在dtime中给出该观测值的第二个时间点,否则给出第一个时间点。例如,对于第 1 天的受试者 1,('4/16/2012 6:25'-'4/16/2012 15:16')<0,因此我们将第一个时间点 '4/16/2012 6:15' 交给这个 obs;('4/16/2012 17:22'-'4/16/2012 15:16')>0,所以我们给这个第二个时间点'4/16/2012 15:16'给这个OBS。预期输出应如下所示:
df3=data.frame(subject = c(rep(1, 12), rep(2, 10)), day =c(1,1,1,1,1,2,3,15,15,15,15,19,1,1,1,1,2,3,15,15,15,15),stime=c('4/16/2012 6:25','4/16/2012 7:01','4/16/2012 17:22','4/16/2012 17:45','4/16/2012 18:13','4/18/2012 6:50','4/19/2012 6:55','5/1/2012 6:28','5/1/2012 7:00','5/1/2012 16:28','5/1/2012 17:00','5/5/2012 17:00','4/23/2012 5:56','4/23/2012 6:30','4/23/2012 16:55','4/23/2012 17:20','4/25/2012 6:32','4/26/2012 6:28','5/8/2012 5:54','5/8/2012 6:30','5/8/2012 15:55','5/8/2012 16:30'), dtime=c('4/16/2012 6:15','4/16/2012 6:15','4/16/2012 15:16','4/16/2012 15:16','4/16/2012 15:16','4/18/2012 7:15','4/19/2012 7:05','5/1/2012 7:15','5/1/2012 7:15','5/1/2012 15:15','5/1/2012 15:15','.','4/23/2012 6:45','4/23/2012 6:45','4/23/2012 16:45','4/23/2012 16:45','4/25/2012 6:45','4/26/2012 6:45','5/8/2012 6:45','5/8/2012 6:45','5/8/2012 15:45','5/8/2012 15:45'))
。
我使用下面的代码来实现这一点,但是,由于缺少第 19 天的"dtime",R 一直给我错误:
df1$dtime <- apply(df1, 1, function(x){
choices <- df2[ df2$subject==as.numeric(x["subject"]) &
df2$day==as.numeric(x["day"]) , "dtime"]
if( as.POSIXct(x["stime"], format="%m/%d/%Y %H:%M") <
as.POSIXct(choices[2],format="%m/%d/%Y %H:%M") ) {
choices[1]
}else{ choices[2] }
} )
Error in if (as.POSIXct(x["stime"], format = "%m/%d/%Y %H:%M") < as.POSIXct(choices[2], : missing value where TRUE/FALSE needed
由于我的数据集很大(大约 15,000 行和 30 列),因此 df2 中缺少一些"dtime"。有谁知道如何解决这个问题?
我认为这可能对你有用:
df1$dtime <- apply(df1, 1, function(x) {
choices <- as.character(df2[ df2$subject==as.numeric(x["subject"]) &
df2$day==as.numeric(x["day"]), "dtime"])
t1 <- as.POSIXct(as.character(x["stime"]), format="%m/%d/%Y %H:%M")
t2 <- as.POSIXct(choices[2], format="%m/%d/%Y %H:%M")
return(ifelse(( t1 < t2 ), choices[1], choices[2]))
})