r - 使用逻辑向量从字符向量中排除 FALSE 元素

Question

我设法做到了以下几点:

stuff <- c("banana_fruit","apple_fruit","coin","key","crap")
fruits <- stuff[stuff %in% grep("fruit",stuff,value=TRUE)]

但我无法通过像这样的通常想法和想法来选择不太健康的东西

no_fruit <- stuff[stuff  %not in% grep("fruit",stuff,value=TRUE)]
#or
no_fruit <- stuff[-c(stuff  %in% grep("fruit",stuff,value=TRUE))]

不工作。后者只是忽略了“-”

Answer 1

> stuff[grep("fruit",stuff)]
[1] "banana_fruit" "apple_fruit" 
> stuff[-grep("fruit",stuff)]
[1] "coin" "key"  "crap"

您只能对数字/整数向量使用负下标，这不符合逻辑，因为:

> -TRUE
[1] -1

如果你想否定一个逻辑向量，使用!:

> !TRUE
[1] FALSE