> a<-datauser[datauser$time<"2014-12-17 00:00:00"&datauser$time>"2014-12-15 24:00:00"&(datauser$item_id %in% dataitem[,1])&datauser$behavior_type=="4",]> > head(a) user_id item_id behavior_type user_geohash item_category
16277 100212013 256506746 4 4582
18232 100226515 285949544 4 4582
29554 100475890 79458119 4 4396
30166 100475890 79458119 4 4396
81038 101289766 141878418 4 94fdbas 11406
81176 101321698 248241836 4 6648
time
16277 2014-12-15 19:00:00
18232 2014-12-16 13:00:00
29554 2014-12-16 00:00:00
30166 2014-12-16 00:00:00
81038 2014-12-15 18:00:00
81176 2014-12-16 12:00:00
可以看到提取的a 是想datauser$time>"2014-12-15 24:00:00",但是却出现了 2014-12-15 19:00:00,81038 2014-12-15 18:00:00。这是怎么回事啊?求大家帮帮忙!