Question

D = c("d", "d", "S", "d")
A = c("d", "a", "a", "x")
X = c("v", "x", "x", "t")
R = c("t", "r", "r", "r")
dat = data.frame(D, A, X, R)

D A X R MajoritySum
d d v t  1
d a x r  4
s a x r  3
d x t r  2

我目前正在尝试添加上图所示的MajoritySum列，该列计算行的值在大多数因子水平变量中的次数。

我遍历数据框以获取每一列的多数类，但现在遇到了困难。

majority = rep(NA, 4)
for(i in c(1:4)){
    majority[i] = 
    names(sort(table(dat[,i]),decreasing = TRUE)[1])
}

> majority
[1] "d" "a" "x" "r"

Answer 1

这是一个基本的R解决方案：

for (i in 1:nrow(MH.factors)) {
    MH.factors$MajoritySum[i] <- sum(MH.factors[i,] == majority)
}

Answer 2

这是使用dplyr的幼稚解决方案：

library(dplyr)

# alternatively you can use if_else(D == majority[1], 1, 0) and so on
dat %>%
  mutate(
    MajoritySum = if_else(D == "d", 1, 0) + 
      if_else(A == "a", 1, 0) + 
      if_else(X == "x", 1, 0) + 
      if_else(R == "r", 1, 0)
  )

#   D A X R MajoritySum
# 1 d d v t           1
# 2 d a x r           4
# 3 S a x r           3
# 4 d x t r           2

计算R中每一行等于向量的列

2 个答案: