I have a list in R some 10,000 elements long. Say I want to select only elements, 5, 7, and 9. I'm not sure how I would do that without a for loop.
我有一个列在R里的10000个元素。假设我只想选择元素，5 7 9。我不知道没有循环该怎么做。
I want to do something like mylist[[c(5,7,9]] but that doesn't work. I've also tried the lapply function but haven't been able to get that working either.
我想做一些类似mylist[c(5,7,9)]的事情，但这行不通。我也尝试过lapply函数，但也没能成功。
1 个解决方案
#1
99
mylist[c(5,7,9)] should do it.
mylist[c(5、7、9)]应该做它。
You want the sublists returned as sublists of the result list; you don't use [[]] (or rather, the function is [[) for that -- as Dason mentions in comments, [[ grabs the element.
您希望子列表作为结果列表的子列表返回;您不需要使用[](或者更确切地说，函数是[])——正如Dason在注释中提到的，[[获取元素]。
#1
99
mylist[c(5,7,9)] should do it.
mylist[c(5、7、9)]应该做它。
You want the sublists returned as sublists of the result list; you don't use [[]] (or rather, the function is [[) for that -- as Dason mentions in comments, [[ grabs the element.
您希望子列表作为结果列表的子列表返回;您不需要使用[](或者更确切地说，函数是[])——正如Dason在注释中提到的，[[获取元素]。