在不同的列中找到相交的行並標記它們

Question

我正在尋找有關如何正確標記數據框中相交行的解決方案。

這樣的

df = data.frame(id=c("good","bad","ugly","dirty","clean","frenzy"),di=c("good",2,"good","dirty",4,"ugly"))

> df
      id    di
1   good  good
2    bad     2
3   ugly  good
4  dirty dirty
5  clean     4
6 frenzy  ugly

我想創建列名match ，如果存在常見的相交行值，則將它們標記為intersected否則為no.intersect 。

我試過了

df%>%
  mutate(match=ifelse(isTRUE(intersect(id,di)),"intersected","no.intersect"))

它輸出

      id    di        match
1   good  good no.intersect
2    bad     2 no.intersect
3   ugly  good no.intersect
4  dirty dirty no.intersect
5  clean     4 no.intersect
6 frenzy  ugly no.intersect

盡管第1行和第4行存在相交。

Answer 1

library(dplyr)

# example dataframe
# (non factor variables)
df = data.frame(id=c("good","bad","ugly","dirty","clean","frenzy"),
                di=c("good",2,"good","dirty",4,"ugly"), 
                stringsAsFactors = F)

# check equaity of values at each row
df %>% mutate(match = ifelse(id == di, "intersected", "no.intersect"))

#       id    di        match
# 1   good  good  intersected
# 2    bad     2 no.intersect
# 3   ugly  good no.intersect
# 4  dirty dirty  intersected
# 5  clean     4 no.intersect
# 6 frenzy  ugly no.intersect    

另外，如果要使用intersect ，可以像這樣使用它：

df %>%
  rowwise() %>%
  mutate(match = ifelse(length(intersect(id,di)) > 0, "intersected", "no.intersect")) %>%
  ungroup()

# # A tibble: 6 x 3
#   id     di    match       
#   <chr>  <chr> <chr>       
# 1 good   good  intersected 
# 2 bad    2     no.intersect
# 3 ugly   good  no.intersect
# 4 dirty  dirty intersected 
# 5 clean  4     no.intersect
# 6 frenzy ugly  no.intersect

因為intersect不是向量化的（所以您需要rowwise ），並且它不返回TRUE或FALSE（所以您不能使用isTRUE ）。 如果有匹配項，它將返回實際值；否則，將不返回任何值。

Answer 2

如果您要比較id和di之間的相等性，請嘗試：

df %>% mutate(match = ifelse(id == di, "intersected", "no.intersect"))