r - 如何按两个条件进行分组并计算所有行是否满足另一个条件

Question

我有以下表单数据:

Household <- rep(c("1", "2", "3", "4"), each = 3) 
Product <- c(21,21,19,18,21,21,11,11,19,16,16,12) 
Discount <- c(0,1,0,0, 0.5,1,0.5,1,0,0,0,1)

data <- data.frame(Household = Household, Product = Product, Discount = Discount)

我想计算一个家庭总是以折扣价购买产品的次数。

Household <- c(2, 3)
Product <- c(21, 11)
result <- data.frame(Household = Household, Product = Product)

非常感谢。

我尝试过按家庭和产品进行分组，并在折扣 >0 时进行汇总，但这告诉了我以折扣购买的家庭的个别购买实例。根据我的查询，我认为 SQL 中的“having”等价物会有所帮助。

Answer 1

使用dplyr我们可以做到:

library(dplyr)

data |>
  count(Household,
        Product,
        wt = Discount > 0) |>
  filter(n > 1)

或者可能更清楚一点:

library(dplyr)

data |>
  group_by(Household, Product) |>
    filter(Discount > 0) |>
    tally() |>
    filter(n > 1) |>
  ungroup()

输出:

# A tibble: 2 × 3
  Household Product     n
  <chr>       <dbl> <int>
1 2              21     2
2 3              11     2