[R] where is a value in my list

[David Winsemius]

  The term "line" in R refers to a sequence of text ending in and  
<EOL> marker, which I doubt is what you meant. Please stop referring  
to the items or elements of a list as "lines" if you hope to  
communicate with R-users.

 > lista[1:2]
[[1]]
[1] 2 4 5 5 6

[[2]]
[1] 3 5 4 2

 > lista[ which(sapply(lista, function(x) any(x == 5))) ]
[[1]]
[1] 2 4 5 5 6

[[2]]
[1] 3 5 4 2

-- 
David.

On Nov 15, 2009, at 11:57 AM, Grzes wrote:

>
> It's excellent!
> Now, if I have a vector k=c( TRUE, TRUE, FALSE) how I may get lines  
> from
> list?
> which (list ?? k) ?
>
>
>
> David Winsemius wrote:
>>
>>
>> On Nov 15, 2009, at 10:47 AM, Grzes wrote:
>>
>>>
>>> But it's not what I wont
>>>
>>> I need get a number of line my list
>>> 5 is in: list[[1]][1] and list[[2]][1] so
>>> I would like to get a vector k = 1,2
>>>
>>
>> I am sorry. I do not understand what you want the second solution
>> offered gave you numbers (and they were the numbers that were for
>> "5"'s rather than one that were not for "5"'s as your offered  
>> solution.
>>
>> If you just want to know which lists contain a 5, but not the  
>> position
>> within the list (which was not what you appeared to be asking..):
>>
>>> which(sapply(lista, function(x) any(x == 5)))
>> [1] 1 2
>>
>>
>>
>>>
>>> David Winsemius wrote:
>>>>
>>>>
>>>> On Nov 15, 2009, at 10:01 AM, Grzes wrote:
>>>>
>>>>>
>>>>> I heve got a list:
>>>>>
>>>>> lista=list()
>>>>> a=c(2,4,5,5,6)
>>>>> b=c(3,5,4,2)
>>>>> c=c(1,1,1,8)
>>>>> lista[[1]]=a
>>>>> lista[[2]]=b
>>>>> lista[[3]]=c
>>>>>
>>>>>> lista
>>>>> [[1]]
>>>>> [1] 2 4 5 5 6
>>>>>
>>>>> [[2]]
>>>>> [1] 3 5 4 2
>>>>>
>>>>> [[3]]
>>>>> [1] 1 1 1 8
>>>>>
>>>>> I would like to know where is number 5 (which line)?
>>>>>
>>>>> For example I have got a loop:
>>>>>
>>>>> k= vector(mode = "integer", length = 3)
>>>>>
>>>>> for(i in 1:3)
>>>>> {
>>>>> for (j in 1:length(lista[[i]])){
>>>>> if ((lista[[i]][j])==5   k[i]= [i])
>>>>> }
>>>>> }
>>>>>
>>>>> This loop is wrong but I would like to get in my vector k sth like
>>>>> this:
>>>>>
>>>>> k = lista[[1]][1], lista[[2]][1]     ...or sth similar
>>>>
>>>> I am a bit confused, since clearly lista[[1]][1] does _not_ == 5.
>>>> It's
>>>> also unclear what type of output you expect ... character, list,
>>>> numeric?
>>>>
>>>> See if these take you any further to your vaguely expressed goal:
>>>>
>>>>> lapply(lista, "%in%", 5)
>>>> [[1]]
>>>> [1] FALSE FALSE  TRUE  TRUE FALSE
>>>>
>>>> [[2]]
>>>> [1] FALSE  TRUE FALSE FALSE
>>>>
>>>> [[3]]
>>>> [1] FALSE FALSE FALSE FALSE
>>>>
>>>>> lapply(lista, function(x) which(x == 5) )
>>>> [[1]]
>>>> [1] 3 4
>>>>
>>>> [[2]]
>>>> [1] 2
>>>>
>>>> [[3]]
>>>> integer(0)
>>>>
>>>>> --
>>>>
>


David Winsemius, MD
Heritage Laboratories
West Hartford, CT