Question

我有一个看起来像这样的大数据框：

   Location       Dttm          Parameter      Unit         Value
1  Airport 2018-01-01 12:00:00 Wind Direction  deg          60
2  Airport 2018-01-01 12:00:00 Wind Speed      m/sec        3.45

显然，这还有更多行，我只是在显示数据示例。我需要旋转数据，以便有一列用于风向和风速。但是，当我运行ivot_wider函数时，会得到如下信息：

   Location      Dttm          Unit     Wind Direction   Wind Speed   
1  Airport 2018-01-01 12:00:00 deg          60                NULL
2  Airport 2018-01-01 12:00:00 m/sec        NULL              3.45

我尝试了各种group_by方法，但是没有找到任何能满足我实际需求的东西，

   Location      Dttm              Wind Direction   Wind Speed   
1  Airport 2018-01-01 12:00:00          60             3.45

我认为，如果我将id_cols设置为Dttm，pivot_wider会为我完成此操作，但这也不起作用。甚至不确定如何真正用谷歌搜索该解决方案，因此我们将为您提供帮助！

Answer 1

我们可以在执行Unit之前删除pivot_wider列

library(dplyr)
library(tidyr)
df1 %>%
   select(-Unit) %>%
   pivot_wider(names_from = Parameter, values_from = Value)
# A tibble: 1 x 4
#   Location Dttm                `Wind Direction` `Wind Speed`
#   <chr>    <dttm>                         <dbl>        <dbl>
#1 Airport  2018-01-01 12:00:00               60         3.45

O在id_cols中指定pivot_wider参数（如@IceCreamToucan所示）

df1 %>% 
   pivot_wider(id_cols = -Unit, names_from = Parameter, values_from = Value)

如果该组有重复的行，请在pivot_wider

之前为该组创建一个序列列

df1 %>% 
   group_by(Parameter) %>% 
   mutate(rn = row_number()) %>% 
   pivot_wider(id_cols = -Unit, names_from = Parameter, values_from = Value) %>% 
   select(-rn)

数据

df1 <- structure(list(Location = c("Airport", "Airport"), Dttm = structure(c(1514826000, 
1514826000), class = c("POSIXct", "POSIXt"), tzone = ""), Parameter = c("Wind Direction", 
"Wind Speed"), Unit = c("deg", "m/sec"), Value = c(60, 3.45)), row.names = c("1", 
"2"), class = "data.frame")

Answer 2

使用from collections import Counter counts = Counter(your_list)可能会更好，但另一种可能性是使用如下所示的pivot_wider。

tidyr::spread

输出

library(tidyr)
library(dplyr)

df1 <- structure(list(Location = c("Airport", "Airport"), Dttm = structure(c(1514826000, 
1514826000), class = c("POSIXct", "POSIXt"), tzone = ""), Parameter = c("Wind Direction", 
"Wind Speed"), Unit = c("deg", "m/sec"), Value = c(60, 3.45)), row.names = c("1", 
"2"), class = "data.frame")

df1 %>%
  select(-Unit) %>%
  spread(Parameter, Value)

Pivot_wider和Group同时？

2 个答案:

数据