数据框中按字符串部分匹配两列

时间:2019-03-02 00:59:07

标签: r

我有一个数据帧,其中包含SELECT Name, Employee.Area, Area.id_area FROM Employee JOIN Area ON Employee.Area = Area.id_area (10个观察值)和Name1,其中包含3个观察值。我有以下玩具示例:

Name2

如果 Name1 Name2 Acadian Hospitals Wellington Bridgewater Trust Associates Zeus Concordia Consulting Acadian Wellington Corporation LLC . Wellington Wealth Management . Prime Acadian Charity 能够匹配Name1中其字符串的一部分,我希望column3中的输出为Name2。 目前,我的代码只能使用TRUE

我的最终输出应如下所示:

pmatch

3 个答案:

答案 0 :(得分:3)

听起来Name2实际上只是一组查找值。在这种情况下,您可以通过将所有值粘贴在一起来构建查找,然后对所有grepl进行一次简单的df$Name2搜索:

df$Is_Matched <- grepl(paste(df$Name2[df$Name2 == "."], collapse = "|"), df$Name1)
#                         Name1      Name2 Is_Matched
#1            Acadian Hospitals Wellington       TRUE
#2 Bridgewater Trust Associates       Zeus      FALSE
#3         Concordia Consulting    Acadian      FALSE
#4   Wellington Corporation LLC          .       TRUE
#5 Wellington Wealth Management          .       TRUE
#6        Prime Acadian Charity          .       TRUE

请注意,这假设Name2中的缺失值被编码为"."而不是NA。更改为缺少值的任何其他编码将很容易。

答案 1 :(得分:2)

您可以使用sapply。没有示例,我认为类似的事情应该起作用。我将在几秒钟内检查一个示例。

df$Is_Matched <- sapply(df$Name2, function(x) any(grepl(x, df$Name1))

编辑:

创建示例数据框很有帮助。 sapply正在导出一个矩阵,其中Name2中的每个单词都有自己的列。因此,您可以使用rowSums(true = 1,false = 0)测试是否有任何行包含true。让我知道您是否有任何问题。

> df <- data.frame(
+   Name1 = c("Acadian Hospitals", "Bridgewater Trust Associates",
+             "Concordia Consulting", "Wellington Corporation LLC",
+             "Wellington Wealth Management", "Prime Acadian Charity"),
+   Name2 = c("Wellington", "Zeus", "Acadian", NA, NA, NA),
+   stringsAsFactors = FALSE
+ )
> 
> match_me <- na.omit(df$Name2)
> df$Is_Matched <- rowSums(sapply(match_me, function(x) grepl(x, df$Name1))) > 0
> df
                         Name1      Name2 Is_Matched
1            Acadian Hospitals Wellington       TRUE
2 Bridgewater Trust Associates       Zeus      FALSE
3         Concordia Consulting    Acadian      FALSE
4   Wellington Corporation LLC       <NA>       TRUE
5 Wellington Wealth Management       <NA>       TRUE
6        Prime Acadian Charity       <NA>       TRUE

答案 2 :(得分:2)

在Mike H.的帮助下:

Name1 = c("Bridgewater Trust Associates", "Acadian Wealth Management", "Wellington Wealth Trust", "Concordia University", "Southern Zeus College", "Parametric Modeling", "Wellington City Corporation", "Hotel Zanzibar") 
Name2 = c("Acadian", "Wellington", "Zeus")

max.len = max(length(Name1), length(Name2))
Name1 = c(Name1, rep(NA, max.len - length(Name1)))
Name2 = c(Name2, rep(NA, max.len - length(Name2)))
column3 <- grepl(paste(Name2, collapse = "|"), Name1)

df <- data.frame(Name1, Name2, column3, stringsAsFactors = FALSE)
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