測試元素是否在列表中並返回0或1

Question

我目前正在嘗試檢查元素是否爲列表的一部分，如果是大小寫則返回1，否則返回0。

我一直在做這個循環，但由於矩陣將會非常大（這裏只提供一個簡單的例子），我想知道是否有一種有效的方法來做到這一點。

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} 
} 

，結果

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

Answer 1

我們可以嘗試%in%

as.integer(names %in% T1_temp) 

或者match

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