如果在 r 中满足条件，则按组删除行答案

【问题标题】：Remove rows by group if a condition meets in r如果在 r 中满足条件，则按组删除行
【发布时间】：2023-02-15 22:01:51
【问题描述】：

我有一个像这样的数据框去向:

df <- data.frame(year = c("2000", "2000", "2001", "2001", "2002", "2002", "2003", "2007", "2008"), 
                 id = c("A", "A", "A", "A", "A", "A", "A", "B", "B"), 
                 product = c("1", "2", "3", "4", "5", "6", "7", "8", "9"), 
                 market = c("CHN", "USA", "CHN", "CAN", "CHN", "ECU", "CHN", "ESP", "IRL"), 
                 FP = c(1, 1, 1, 1, 1, 1, 1, 1, 1),
                 FM = c(1, 1, 0, 1, 0, 1, 0, 1, 1),
                 first_success = c(0,0,0,0,2002,2002,2002,0, 0)
                 )

我想（通过 id）删除 first_success 年之后的观察结果（在变量中定义第一次成功并采用成功的年份的价值）。如果给定的 id（例如 B）没有成功，那么我想保留这些零。因此，在这种情况下，我只会删除第 7 行：

df_new <- data.frame(year = c("2000", "2000", "2001", "2001", "2002", "2002", "2007", "2008"), 
                 id = c("A", "A", "A", "A", "A", "A", "B", "B"), 
                 product = c("1", "2", "3", "4", "5", "6", "8", "9"), 
                 market = c("CHN", "USA", "CHN", "CAN", "CHN", "ECU", "ESP", "IRL"), 
                 FP = c(1, 1, 1, 1, 1, 1, 1, 1),
                 FM = c(1, 1, 0, 1, 0, 1, 1, 1),
                 first_success = c(0,0,0,0,2002,2002,0,0)
                 )

我尝试了以下方法：

df %>% 
 group_by(id) %>%
 subset(., first_succes!=0 & first_success<year)
 filter(if(any(first_success)!=0) year<=first_success else TRUE)

但是 filter 保留了表达式，而不是删除它（与 subset() 相同）。

任何想法？

【问题讨论】：

标签： r if-statement dplyr tidyverse

【解决方案1】：

你可以这样做：

library(dplyr) #1.1.0
df %>% 
  filter(first_success == 0 | year <= first_success, .by = id)

  year id product market FP FM first_success
1 2000  A       1    CHN  1  1             0
2 2000  A       2    USA  1  1             0
3 2001  A       3    CHN  1  0             0
4 2001  A       4    CAN  1  1             0
5 2002  A       5    CHN  1  0          2002
6 2002  A       6    ECU  1  1          2002
7 2007  B       8    ESP  1  1             0
8 2008  B       9    IRL  1  1             0

【讨论】：