使用pivot_wider获取true或false

Question

我正在尝试使用pivot_wider来获取1991 - 1995年间每个国家/地区的二进制结果，如下表所示：

+------+-------+--------+--------+
| year | USA   | Israel | Sweden |
| 1991 | FALSE | TRUE   | TRUE   |
| 1992 | FALSE | FALSE  | TRUE   |
| 1993 | FALSE | TRUE   | TRUE   |
| 1994 | FALSE | FALSE  | TRUE   |
| 1995 | TRUE  | TRUE   | TRUE   |
+------+-------+--------+--------+

当然，除了真/假之外，任何二进制指示都很好。

但是，我的数据框看起来像：

 country =  c("Sweden", "Sweden", "Sweden", "Sweden", "Sweden", "Israel", "Israel",
                   "Israel", "USA")  
    year = c(1991,1992,1993,1994,1995,1991,1993,1995,1995)
      df = as.data.frame(cbind(year,country))
    df


+---------+------+
| country | Year |
| Sweden  | 1991 |
| Sweden  | 1992 |
| Sweden  | 1993 |
| Sweden  | 1994 |
| Sweden  | 1995 |
| Israel  | 1991 |
| Israel  | 1993 |
| Israel  | 1995 |
| USA     | 1995 |
+---------+------+

我尝试了以下代码并获得了下面的结果，这不是我想要的

  library(dplyr)
    df2 =  df %>%
      group_by(country) %>%
      mutate(row = row_number()) %>%
      pivot_wider(names_from = country, values_from = year) %>%
      select(-row)
    df2

+------+--------+--------+
| USA  | Israel | Sweden |
| 1995 | 1991   | 1991   |
| NA   | 1993   | 1992   |
| NA   | 1995   | 1993   |
| NA   | NA     | 1994   |
| NA   | NA     | 1995   |
+------+--------+--------+

Answer 1

你可以试试这个：

library(dplyr)
library(tidyr)
df %>% mutate(val=1) %>% pivot_wider(names_from = country,values_from = val) %>% 
  mutate(across(-year, ~replace_na(.x, 0))) %>%
  mutate(across(-year, ~ifelse(.x==1, TRUE,FALSE)))

输出：

# A tibble: 5 x 4
  year  Sweden Israel USA  
  <fct> <lgl>  <lgl>  <lgl>
1 1991  TRUE   TRUE   FALSE
2 1992  TRUE   FALSE  FALSE
3 1993  TRUE   TRUE   FALSE
4 1994  TRUE   FALSE  FALSE
5 1995  TRUE   TRUE   TRUE 

Answer 2

这是一个

data.table

解决方案

library( data.table )
#custom function, odetermins is the length of a vector >1 (TRUE/FALSE)
cust_fun <- function(x) length(x) > 0
#cast to wide, aggregating with the custom function above
dcast( setDT(df), year ~ country, fun.aggregate = cust_fun )

#    year Israel Sweden   USA
# 1: 1991   TRUE   TRUE FALSE
# 2: 1992  FALSE   TRUE FALSE
# 3: 1993   TRUE   TRUE FALSE
# 4: 1994  FALSE   TRUE FALSE
# 5: 1995   TRUE   TRUE  TRUE