r—风向的重编码因子水平

Question

我希望将以下因素重新编码为主要风向分量。返回一个错误，我不明白。我真的需要一些帮助来解决这个问题。

变量W.G.Dir为因子形式，有16个水平。

weather$W.G.Dir <- factor(recode(weather$W.G.Dir,
`Southerly` = c(
"SSE", "S",
"SSW"
),
`Easterly` = c("ENE", "E", "ESE"),
`Northerly` = c("NNE", "N", "NNW"),
`Westerly` = c("WNW", "W", "WSW"),
`S'East` = "SE", `S'West` = "SW", `N'East` =
"NE", `N'West` = "NW"
))

错误:Southerly的长度必须是16或1，而不是3.

Answer 1

因为只有16个点，所以我想创建一个1:1的映射，然后创建一个新的因子来替换旧的因子:

all_points <- c("N", "NNE", "NE", "ENE", "E", "ESE", "SE", "SSE",
"S", "SSW", "SW", "WSW", "W", "WNW", "NW", "NNW")
full <- c("North", "North", "NorthEast", "East", "East", 
"East", "SouthEast", "South", "South", "South", 
"SouthWest", "West", "West", "West", "NorthWest", "North")
weather$W.G.Dir <- factor(full[match(weather$W.G.Dir, all_points)], 
unique(full))
weather
#>      W.G.Dir
#> 1      South
#> 2       East
#> 3  SouthEast
#> 4      North
#> 5      North
#> 6       West
#> 7  SouthEast
#> 8  SouthWest
#> 9       West
#> 10     North

---

数据组成的例子

set.seed(1)
all_points <- c("N", "NNE", "NE", "ENE", "E", "ESE", "SE", "SSE",
"S", "SSW", "SW", "WSW", "W", "WNW", "NW", "NNW")
weather <- data.frame(W.G.Dir = factor(sample(all_points, 10, TRUE), all_points))
weather
#>    W.G.Dir
#> 1        S
#> 2      ENE
#> 3       SE
#> 4        N
#> 5      NNE
#> 6        W
#> 7       SE
#> 8       SW
#> 9      WNW
#> 10     NNE