如何在R中聚合數據

Question

我希望創建一個基於區域的新數據框架，並根據“年份”，“屬性類型”以及是舊的還是新的，按照每個區域的計數對數據集進行分組。

我已經嘗試了聚合函數但是丟失了其他變量的值。 以下是數據集

 Property.Type Old.New Town.City District             County         Date 
 1 D             N       BARKING   BARKING AND DAGENHAM GREATER LONDON 2012 
 2 D             Y       BARKING   BARKING AND DAGENHAM GREATER LONDON 2012 
 3 D             N       BARKING   BARKING AND DAGENHAM GREATER LONDON 2012 
 4 D             N       DAGENHAM  BARKING AND DAGENHAM GREATER LONDON 2012 
 5 D             N       DAGENHAM  BARKING AND DAGENHAM GREATER LONDON 2012 

我想重新安排數據，所以我將分區作為我的ID和每個類別的不同幀，例如：

by year
District 2012 2013 2014 2015
Barking  100  500  700 800

by Old.New and year 

District New  Old
Barking  50    70

by property type and year
District New2012  Old2012
Barking  50    70

Answer 1

沒有完整的數據框，它有點難以幫助，但是這里有一些代碼塊，向您展示如何使用tidyverse庫來聚合數據。

首先使用提供的數據重新創建數據幀：

Property.Type <- c("D","D","D","D","D")
Old.New <- c("N","Y","N","N","N")
Town.City <- c("BARKING","BARKING","BARKING","DAGENHAM","DAGENHAM")
District <- c("BARKING AND DAGENHAM","BARKING AND DAGENHAM","BARKING AND DAGENHAM","BARKING AND DAGENHAM","BARKING AND DAGENHAM")
County <- c("GREATER LONDON","GREATER LONDON","GREATER LONDON","GREATER LONDON","GREATER LONDON")
Date <- c(2012,2012,2012,2012,2012)    
df <- data.frame(Property.Type,Old.New,Town.City,District,County,Date)

然后通過一些列聚合：

> df %>% group_by(Town.City) %>% summarise(n = n())
# A tibble: 2 x 2
  Town.City     n
  <fct>     <int>
1 BARKING       3
2 DAGENHAM      2
> 
> df %>% group_by(Date, Town.City) %>% summarise(n = n())
# A tibble: 2 x 3
# Groups:   Date [?]
   Date Town.City     n
  <dbl> <fct>     <int>
1  2012 BARKING       3
2  2012 DAGENHAM      2
> 
> df %>% group_by(Date, Town.City) %>% summarise(n = n())
# A tibble: 2 x 3
# Groups:   Date [?]
   Date Town.City     n
  <dbl> <fct>     <int>
1  2012 BARKING       3
2  2012 DAGENHAM      2
> 
> df %>% group_by(Property.Type, Date) %>% summarise(n = n())
# A tibble: 1 x 3
# Groups:   Property.Type [?]
  Property.Type  Date     n
  <fct>         <dbl> <int>
1 D              2012     5

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