测试元素是否在列表中并返回 0 或 1

Question

我目前正在尝试检查一个元素是否是列表的一部分，如果是则返回 1，否则返回 0。

我一直在为此做一个循环，但由于矩阵将非常大（这里仅提供一个简单的示例），我想知道是否有一种有效的方法来做到这一点。

rm(list=ls())   # clear memory
names <- c("a","b","c","d","e","f","g","h","i","j","k50","l50","m50","n50","o50")

proba <- c(1,1,1,1,1,1,1,1,1,1,0.5,0.5,0.5,0.5,0.5)

T1_temp <- sample(names,4,prob=proba)

# Loop to check which element of T1_temp is included in names
T1 <- c()
for (i in 1:length(names)){
  if (is.element(names[i],T1_temp)){T1[i]=1}
  else{T1[i]=0}
}

结果是

 [1] 0 1 0 0 1 1 0 0 1 0 0 0 0 0 0

Answer 1

我们可以试试%in%

as.integer(names %in% T1_temp)

或match

 +(!is.na(match(names,T1_temp)))