R 创建基于值采用列名的新列

我有一个包含二进制值的表，我想将其汇总到一列中。以下是一个例子：

df <- data.frame("User" = c("User A", "User B", "User C"), "quality 1" = c(0,0,1), "quality 2" = c(1,0,0), "quality 3" = c(0,1,0))

---

您可以尝试添加到相同的

df

：

df$qualityNumber <- apply(df[,-1],1,function(x) names(x)[which(x==1)])

    User quality.1 quality.2 quality.3 qualityNumber
1 User A         0         1         0     quality.2
2 User B         0         0         1     quality.3
3 User C         1         0         0     quality.1

另一种方法：

df$qualityNumber <- names(df)[max.col(df == 1, ties.method = "first")]

---

这是完美的；非常感谢。

df$qualityNumber <- apply(df[,-1],1,function(x) names(x)[which(x==1)])

    User quality.1 quality.2 quality.3 qualityNumber
1 User A         0         1         0     quality.2
2 User B         0         0         1     quality.3
3 User C         1         0         0     quality.1

df[,c(1,5)]

    User qualityNumber
1 User A     quality.2
2 User B     quality.3
3 User C     quality.1

df$qualityNumber <- names(df)[max.col(df == 1, ties.method = "first")]

> df
    User quality.1 quality.2 quality.3 qualityNumber
1 User A         0         1         0     quality.2
2 User B         0         0         1     quality.3
3 User C         1         0         0     quality.1