数据框中两个逗号分隔因子之间的匹配数

时间:2014-03-28 23:38:09

标签: r match

我的数据框看起来像这样:

Row    ID1    ID2    Colors1        Colors2
1      1      2      Green, Blue    Red, Orange
2      1      3      Green, Orange  Orange, Red 

我想创建一个计算,告诉我Colors1和Colors2之间的颜色计数。期望的结果如下:

Row    ID1    ID2    Colors1                Colors2         Common 
1      1      2      Green, Blue, Purple    Green, Purple   2     #Green, Purple
2      1      3      Green, Orange          Orange, Red     1     #Orange

2 个答案:

答案 0 :(得分:2)

另一种方法是将第一列视为正则表达式,以便在第二列中进行搜索,并使用“stringi”包来促进模式的矢量化搜索。

df <- structure(list(Colors1 = c("Green, Blue, Purple", "Green, Blue", 
"Green, Blue, Purple"), Colors2 = c("Green, Purple", "Green, Purple", 
"Orange, Red")), .Names = c("Colors1", "Colors2"), row.names = c("2", 
"21", "3"), class = "data.frame")

df
#                Colors1       Colors2
# 2  Green, Blue, Purple Green, Purple
# 21         Green, Blue Green, Purple
# 3  Green, Blue, Purple   Orange, Red

library(stringi)
stri_extract_all_regex(df$Colors2, gsub(", ", "|", df$Colors1))
# [[1]]
# [1] "Green"  "Purple"
# 
# [[2]]
# [1] "Green"
# 
# [[3]]
# [1] NA

stri_count_regex(df$Colors2, gsub(", ", "|", df$Colors1))
# [1] 2 1 0

基本上,我在那里做的是使用gsub将“Colors1”列转换为正则表达式搜索模式,看起来像"Green|Blue|Purple"而不是"Green, Blue, Purple",并将其用作我在上面演示的每个“stringi”函数中的搜索模式。

答案 1 :(得分:1)

您可以使用:

col1 <- strsplit(df$Colors1, ", ")
col2 <- strsplit(df$Colors2, ", ")
df$Common <- sapply(seq_len(nrow(df)), function(x) length(intersect(col1[[x]], col2[[x]])))

实施例

df <- data.frame(Colors1 = c('Green, Blue', 'Green, Blue, Purple'), Colors2 = c('Green, Purple', 'Orange, Red'), stringsAsFactors = FALSE)
col1 <- strsplit(df$Colors1, ", ")
col2 <- strsplit(df$Colors2, ", ")
df$Common <- sapply(seq_len(nrow(df)), function(x) length(intersect(col1[[x]], col2[[x]])))
df
#               Colors1         Colors2   Common
# 1         Green, Blue   Green, Purple        1
# 2 Green, Blue, Purple   Orange, Red          0