R - 合并两个数据帧 - sort.list(bx[m$xi]) 中的错误："x"对于"sort.list"必须是原子的

Question

我正在尝试通过key_date每个数据帧中设置的数据帧来合并到数据帧：

> merge <- merge(x = df1, y = df2, by = "key_date", all.x = TRUE)

错误：

Error in sort.list(bx[m$xi]) : 'x' must be atomic for 'sort.list'
Have you called 'sort' on a list?

df1的结构：

'data.frame':   192 obs. of  8 variables:
 $ date    : POSIXct, format: "2017-02-03 00:00:00" ...
 $ NO2     : num  7.4 6.7 7 6.1 5.8 8.8 9 8.5 8.1 7.6 ...
 $ key_date: POSIXlt, format: "2017-02-03" ...
 $ site    : chr  "anon1" "anon1" "anon1" "anon1" ...
 $ code    : chr  "anon1" "anon1" "anon1" "anon1" ...

df2的结构：

'data.frame':   2 obs. of  6 variables:
 $ airport : chr  "LCY" "LCY"
 $ key_date: chr  "2017-02-04" "2017-02-03"
 $ ws      : num  4 13
 $ wd      : num  161 185
 $ tempi   : num  7 8
 $ humidity: num  85 78
> dput(df2)
structure(list(airport = c("LCY", "LCY"), key_date = c("2017-02-04", 
"2017-02-03"), ws = c(4, 13), wd = c(161, 185), tempi = c(7, 
8), humidity = c(85, 78)), .Names = c("airport", "key_date", 
"ws", "wd", "tempi", "humidity"), row.names = c(NA, -2L), class = "data.frame")

出了什么问题？有什么想法吗？

Answer 1

df2$key_data的

类与df1类不同

#df2$key_date <- as.Date(df2$key_date, "%Y-%M-%d")
df2$key_date <- as.POSIXct(df2$key_date)
mdf <- merge(x = df1, y = df2, by = "key_date", all.x = TRUE)

编辑：

"

AEST"和"GMT"中的日期与两个df中的时间有所不同。

df2$key_date <- as.POSIXct(df2$key_date)
df2$key_date
# [1] "2017-02-04 AEST" "2017-02-03 AEST"
df1$key_date
#[1] "2017-02-03 GMT" "2017-02-03 GMT" "2017-02-03 GMT" "2017-02-03 GMT"
#[5] "2017-02-03 GMT" "2017-02-03 GMT"
df2$key_date <- as.character(df2$key_date)
df1$key_date <- as.character(df1$key_date)
merge(x = df1, y = df2, by = "key_date", all.x = TRUE)
# key_date                date NO2 PM10_1 PM10_2 PM10_3  site  code
# 1 2017-02-03 2017-02-03 10:00:00 7.4   18.3     NA     NA anon1 anon1
# 2 2017-02-03 2017-02-03 10:15:00 6.7     NA   27.5     NA anon1 anon1
# 3 2017-02-03 2017-02-03 10:30:00 7.0     NA   27.9     NA anon1 anon1
# 4 2017-02-03 2017-02-03 10:45:00 6.1     NA   28.9     NA anon1 anon1
# 5 2017-02-03 2017-02-03 11:00:00 5.8   21.1   28.2     NA anon1 anon1
# 6 2017-02-03 2017-02-03 11:15:00 8.8     NA   28.1     NA anon1 anon1
# airport ws  wd tempi humidity
# 1     LCY 13 185     8       78
# 2     LCY 13 185     8       78
# 3     LCY 13 185     8       78
# 4     LCY 13 185     8       78
# 5     LCY 13 185     8       78
# 6     LCY 13 185     8       78

Answer 2

我认为这是因为您在两个数据框中的关键日期格式不同，一个是字符，另一个是POSIXct将它们转换为相同的格式，然后重试。