Создать переменную на основе других значений в другом наборе данных

Question

Я хочу создать переменные, подсчитывающие количество мест каждой партии для каждого муниципалитета, поэтому я получаю следующее:

df <- data.frame(
  stringsAsFactors = FALSE,
          municipality= c("Aa en Hunze","Aa en Hunze",
                       "Aa en Hunze","Aalburg","Aalburg","Aalsmeer",
                       "Aalsmeer","Aalten","Aalten","Achtkarspelen","Achtkarspelen",
                       "Alblasserdam","Alblasserdam","Alblasserdam",
                       "Albrandswaard","Albrandswaard","Almelo","Almelo","Almelo",
                       "Almelo","Almere","Almere","Almere","Almere",
                       "Alphen-Chaam","Alphen-Chaam","Ameland","Ameland","Amersfoort",
                       "Amersfoort","Amersfoort","Amersfoort","Amstelveen",
                       "Amstelveen","Amstelveen","Amstelveen","Amsterdam",
                       "Amsterdam","Amsterdam","Amsterdam"),
            party = c("VVD","CDA",
                       "Democraten 66 (D66)","CDA","VVD","CDA","VVD","CDA","VVD","CDA",
                       "VVD","CDA","Democraten 66 (D66)","VVD","VVD","CDA",
                       "CDA","Democraten 66 (D66)","SP (Socialistische Partij)",
                       "VVD","Democraten 66 (D66)","VVD",
                       "SP (Socialistische Partij)","CDA","CDA","VVD","CDA","VVD",
                       "Democraten 66 (D66)","VVD","CDA","SP (Socialistische Partij)",
                       "VVD","Democraten 66 (D66)","CDA",
                       "SP (Socialistische Partij)","Democraten 66 (D66)",
                       "SP (Socialistische Partij)","VVD","CDA"),
      seats= c(3L,2L,2L,3L,1L,6L,6L,7L,
                       2L,5L,1L,3L,2L,2L,6L,2L,6L,4L,4L,3L,6L,5L,
                       4L,2L,4L,1L,3L,1L,9L,5L,4L,4L,9L,8L,3L,3L,
                       14L,6L,6L,1L)
)

I хотите создать, например, переменную с именем VVD, а затем все количество мест на муниципалитет.

^{Создано 16.06.2020 с помощью пакета (v0.3.0)}

Я не знаю, как это закодировать в r, может ли кто-нибудь мне помочь?

Answer 1

Вы можете использовать xtabs для подсчета мест на муниципалитета и партии .

xtabs(seats ~ municipality + party, df)
#               party
#municipality    CDA Democraten 66 (D66) SP (Socialistische Partij) VVD
#  Aa en Hunze     2                   2                          0   3
#  Aalburg         3                   0                          0   1
#  Aalsmeer        6                   0                          0   6
#  Aalten          7                   0                          0   2
#  Achtkarspelen   5                   0                          0   1
#  Alblasserdam    3                   2                          0   2
#  Albrandswaard   2                   0                          0   6
#  Almelo          6                   4                          4   3
#  Almere          2                   6                          4   5
#  Alphen-Chaam    4                   0                          0   1
#  Ameland         3                   0                          0   1
#  Amersfoort      4                   9                          4   5
#  Amstelveen      3                   8                          3   9
#  Amsterdam       1                  14                          6   6