基于单独列中的字符串匹配，有条件地替换跨多列的值

Question

我试图基于不同列中的字符串匹配来有条件地替换多列中的值，但我希望能够使用cross()函数在单行代码中这样做，但我不断得到对我来说不太有意义的错误。我觉得这可能是一个简单的解决方案，所以如果有人能给我指出正确的方向，那将是很棒的！

df <- data.frame("type" = c("Park", "Neighborhood", "Airport", "Park", "Neighborhood", "Neighborhood"),
               "total" = c(34, 56, 75, 89, 21, 56),
               "group_a" = c(30, 26, 45, 60, 3, 46),
               "group_b" = c(4, 30, 30, 29, 18, 10))

# working but not concise
df %>%
  mutate(total = ifelse(str_detect(type, "Park"), NA, total),
         group_a = ifelse(str_detect(type, "Park"), NA, group_a),
         group_b = ifelse(str_detect(type, "Park"), NA, group_b))

  
# concise but not working
df %>% mutate(across(total, group_a, group_b), ifelse(str_detect(type, "Park"), NA, .))

这是产生此错误的数据的一个小样本：

df <- structure(list(Org = c("OrgName", "OrgName", "OrgName", "OrgName", 
"OrgName", "OrgName", "OrgName", "OrgName", "OrgName", "OrgName"
), nCode = c("M34", "R36", "R46", "X29", "M31", "K39", "Q12", 
"Q39", "X41", "K27"), Attempts = c(100, 100, 100, 100, 100, 100, 
100, 100, 100, 100), Canvasses = c(80, 80, 80, 80, 80, 80, 80, 
80, 80, 80), Completes = c(50, 50, 50, 50, 50, 50, 50, 50, 50, 
50), van_nocc_id = c(999, 999, 999, 999, 999, 999, 999, 999, 
999, 999), van_name = c("M-Upper West Side", "SI-Rosebank", "SI-Tottenville", 
"BX-park-cemetery-etc-Bronx", "M-Stuyvesant Town-Cooper Village", 
"BK-Kensington", "Q-Broad Channel", "Q-Lindenwood", "BX-Wakefield", 
"BK-East New York"), boro_short = c("M", "SI", "SI", "BX", "M", 
"BK", "Q", "Q", "BX", "BK"), long_name = c("Upper West Side", 
"Rosebank", "Tottenville", "park-cemetery-etc-Bronx", "Stuyvesant Town-Cooper Village", 
"Kensington", "Broad Channel", "Lindenwood", "Wakefield", "East New York"
)), row.names = c(NA, -10L), class = "data.frame")

错位关闭支架的诅咒！感谢大家的帮助...正确的解决方案是df%>%mutate（跨（c（尝试、画布、完成）,~ifelse（str_detect（long_name,“park-parchemely”）,NA,.））

Answer 1

如果使用新引入的函数across（这是处理此任务的正确方法），则必须在across本身中指定要应用的函数。在本例中，函数ifelse(...)必须是purrr样式的lambda（因此从~开始）。签出anth文档并查找参数.cols和.fns。

df %>% 
  mutate(across(c(total, group_a, group_b), ~ifelse(str_detect(type, "Park"), NA, .)))

输出

#           type total group_a group_b
# 1         Park    NA      NA      NA
# 2 Neighborhood    56      26      30
# 3      Airport    75      45      30
# 4         Park    NA      NA      NA
# 5 Neighborhood    21       3      18
# 6 Neighborhood    56      46      10