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问题

我有一个数据集，其中包含许多相同类型的变量，这些变量可以包含相同的值。我想检查在这些变量中，我们是否可以在一系列值中找到一个值。

例子

假设我们有一个包含 3 个因子类型变量DAS1, DAS2,的数据集DAS3。这些变量的可能值是c("0", "1", "x", "y")（请注意，我并不是试图区分数字和字母。将每个值视为字符）。

library(data.table)

start <- data.table::data.table(DAS1 = c("0","1","x","0","1","0","1"),
                       DAS2 = c("x","y","0","0","x","1","0"),
                       DAS3 = c("1","1","y","1","x","y","0"))

我的目标是找到哪一行包含至少一个值"x"或的观察值"y"。

result <- data.table::data.table(DAS1 = c("0","1","x","0","1","0","1"),
                       DAS2 = c("x","y","0","0","x","1","0"),
                       DAS3 = c("1","1","y","1","x","y","0"),
                       xy = c(T,T,T,F,T,T,F))

健康）状况

我真的想用这个包来做这data.table件事，而不是dplyr因为我主要使用data.table并且如果没有必要的话我不喜欢在两个包之间切换。

由@lovalery 回答

start[, xy := apply(start[,c("DAS1", "DAS2", "DAS3")],1, function(x) any(x %in% c("x", "y")))][]