您好,我有两个数据帧,每个数据帧都有不同的时间戳格式。 组织DF1
为m/d/YYYY H:M
和DF2
。YYYYmmdd
我想根据日期(月、日和年)的时间戳合并这些数据帧,我不关心合并的时间。当我尝试合并时,结果是一个包含 NAts
列的数据框。我认为这是因为时间不匹配,虽然DF2
不显示时间,但我认为它被识别为 00:00:00,因此合并不起作用。有没有办法忽略时间戳中的时间?
我尝试了以下方法。
DF1 <- read.csv("DF1.csv",header=T)
DF2 <- read.csv("DF2.csv",header=T)
DF1$ts <- strptime(DF1$ts, "%m/%d/%Y %H:%M)
DF2$ts <- strptime(DF2$ts, "%Y%m%d")
DF1$ts <- as.POSIXct(DF1$ts)
DF2$ts <- as.POSIXct(DF2$ts)
try <- merge(DF1, DF2, by="ts")
#dput DF1 (sample)
DF1 <- structure(list(LENGTH = c(40, 33.6, 30, 30, 40, 43.5, 50, 40,
62.5, 30), pLENGTH = c(0, 0.297619048, 0, 1, 0, 0, 1, 0, 0.16,
0.666666667), LENGTH2 = c(30.7, NA, 30, NA, 25.1, 39.6, 50,
NA, NA, NA), BURN = c(1L, NA, 1L, NA, 1L, 1L, 1L, NA, NA,
NA), pBURN = c(0.7675, NA, 1, NA, 0.6275, 0.910344828, 1, NA,
NA, NA), ts = structure(c(1344916800, NA, 1339819200, NA,
1339646400, 1345003200, 1340769600, NA, NA, NA), class = c("POSIXct",
"POSIXt"), tzone = "")), .Names = c("LENGTH", "pLENGTH", "LENGTH2",
"BURN", "pBURN", "ts"), row.names = c(135L, 242L, 154L,
56L, 265L, 151L, 328L, 160L, 90L, 364L), class = "data.frame")
#dput DF2 (sample)
DF2<- structure(list(TIMESTAMP = structure(c(1325883600, 1330030800,
1337371200, 1339876800, 1339531200, 1350590400, 1325797200, 1341950400,
1335556800, 1340827200), class = c("POSIXct", "POSIXt")), P = c(0,
0, 0, 0, 1.3, 0, 0, 0, 0, 0), WS = c(4.023, 5.364, 4.917,
3.129, 4.023, 4.023, 3.576, 4.023, 2.235, 2.682), WD = c(165,
217.5, 34.5, 292.75, 167.75, 172.75, 319.25, 129.5, 148, 196)), .Names = c("ts",
"P", "WS", "WD"), row.names = c(6L, 54L, 139L, 286L,
164L, 292L, 5L, 192L, 118L, 121L), class = "data.frame")