使用多个匹配对 R 中的多个列进行子集 [英] Subset multiple columns in R with multiple matches

问题描述

我想做一个与此线程类似的事情:子集R 中的多列 - 更优雅的代码?

I want to do a similar thing as in this thread: Subset multiple columns in R - more elegant code?

我有这样的数据:

df=data.frame(x=1:4,Col1=c("A","A","C","B"),Col2=c("A","B","B","A"),Col3=c("A","C","C","A"))
criteria="A"

我想要做的是subsetcriteria在至少两列中满足的数据，也就是at中的string三列中至少有两列是A.在上述情况下，subset 将是数据帧 df 的第一行和最后一行.

What I want to do is to subset the data where criteria is meet in at least two columns, that is the string in at least two of the three columns is A. In the case above, the subset would be the first and last row of the data frame df.

推荐答案

您可以使用 rowSums :

df[rowSums(df[-1] == criteria) >= 2, ]

#  x Col1 Col2 Col3
#1 1    A    A    A
#4 4    B    A    A

如果 criteria 的长度是 >1 你不能直接使用 == 在这种情况下使用 sapply 和 %in%.

If criteria is of length > 1 you cannot use == directly in which case use sapply with %in%.

df[rowSums(sapply(df[-1], `%in%`, criteria)) >= 2, ]

---

在 dplyr 中，您可以将 filter 与 rowwise 一起使用:

---

In dplyr you can use filter with rowwise :

library(dplyr)
df %>%
  rowwise() %>%
  filter(sum(c_across(starts_with('col')) %in% criteria) >= 2)

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