tidyr - 传播“无效的列规范”

Question

我想将以下data.frame的DATE传播到列中，并将年份放在行中。我的数据结构是：

> str(df)
'data.frame':   836 obs. of  3 variables:
 $ DATE: Date, format: "2014-01-03" "2014-01-04" "2014-01-06" "2014-01-07" ...
 $ VALUE    : num  1 3 1 1 2 6 1 2 1 1 ...
 $ YEAR      : chr  "2014" "2014" "2014" "2014" ...

spread(df, key=DATE, value=VALUE)

但是我收到错误消息“无效的列规范”。是不是为此传播了正确的功能？

编辑：

> str(dfTest)
'data.frame':   836 obs. of  3 variables:
 $ DATE: Date, format: "2015-01-16" "2014-01-06" "2016-07-28" "2016-05-31" ...
 $ VALUE    : num  2 1 3 1 2 22 5 1 4 2 ...
 $ YEAR      : int  2015 2014 2016 2016 2016 2016 2017 2016 2015 2014 ...
> 
> head(dfTest)
  DATE        VALUE YEAR
1 2015-01-16      2 2015
2 2014-01-06      1 2014
3 2016-07-28      3 2016
4 2016-05-31      1 2016
5 2016-04-28      2 2016
6 2016-12-23     22 2016
> spread(dfTest, key=dfTest$DATE, value=dfTest$VALUE)
Error: Invalid column specification

Answer 1

我无法重现你的问题。

脚本

library(tidyr)

df <- data.frame(
    DATE = c("2014-01-03", "2014-01-04", "2015-01-06", "2015-01-07", "2016-01-03", "2016-01-04", "2017-01-06", "2017-01-07"),
    VALUE = c(1, 3, 6, 2, 4, 3, 4, 1),
    YEAR = c("2014", "2014", "2015", "2015", "2016", "2016", "2017", "2017")
    )

df$DATE <- as.Date(df$DATE)
df$YEAR <- as.character(df$YEAR)
str(df)

spread(df, key = DATE, value = VALUE)

输出

#str(df)
'data.frame':    8 obs. of  3 variables:
 $ DATE : Date, format: "2014-01-03" "2014-01-04" "2015-01-06" "2015-01-07" ...
 $ VALUE: num  1 3 6 2 4 3 4 1
 $ YEAR : chr  "2014" "2014" "2015" "2015" ...

#spread(df, key = DATE, value = VALUE)
  YEAR 2014-01-03 2014-01-04 2015-01-06 2015-01-07 2016-01-03 2016-01-04 2017-01-06 2017-01-07
1 2014          1          3         NA         NA         NA         NA         NA         NA
2 2015         NA         NA          6          2         NA         NA         NA         NA
3 2016         NA         NA         NA         NA          4          3         NA         NA
4 2017         NA         NA         NA         NA         NA         NA          4          1