r - 按组在多列上汇总唯一值

Question

我有以下问题：

我的数据集包含许多不同武器系统（级别）的国家/地区年度观察结果。我想知道每个组（国家）在数据集的时间跨度内有多少不同的系统（唯一值）。

简化后，数据集如下所示：

a <- c("Greece", "Greece", "Belgium", "Belgium", "Germany", "Germany")
b <- c(1980, 1981, 1980, 1981, 1980, 1981)
c1 <- c("Weapon1", "Weapon1", "Weapon5", "Weapon5", "Weapon3", "Weapon2")
d  <- c("Weapon2", "Weapon4", "Weapon2", "Weapon2", "Weapon1", "Weapon3")
e <- c("Weapon3", "Weapon3", "Weapon3", "Weapon4", "Weapon2", NA)

df <- data.frame(a,b,c1,d,e)

        a    b      c1       d       e
1  Greece 1980 Weapon1 Weapon2 Weapon3
2  Greece 1981 Weapon1 Weapon4 Weapon3
3 Belgium 1980 Weapon5 Weapon2 Weapon3
4 Belgium 1981 Weapon5 Weapon2 Weapon4
5 Germany 1980 Weapon3 Weapon1 Weapon2
6 Germany 1981 Weapon2 Weapon3    <NA>

所以在示例代码中，德国总共部署了 3 种不同的武器系统。我怎样才能做到这一点？

谢谢大家！

标签： runique

Answer 1

library(tidyverse)

df %>%
  pivot_longer(cols = c(c1, d, e)) %>%
  group_by(a) %>%
  filter(!is.na(value)) %>%
  distinct(value) %>%
  summarize(n=n())

这使：

# # A tibble: 3 x 2
#   a           n
#   <chr>   <int>
# 1 Belgium     4
# 2 Germany     3
# 3 Greece      4