[R] request: How can we ignore a component of list having no element

[Adaikalavan Ramasamy]

Try
	x[ !sapply(x, is.null) ]


hadley wickham wrote:
> An alternative approach would be to store 0 x 0 matrices instead of
> NULLs.  This way every object in your list is a consistent type.
> 
> Hadley
> 
> On Wed, Oct 15, 2008 at 5:23 AM, Muhammad Azam <mazam72 at yahoo.com> wrote:
>> Dear friends
>> There is a list of arrays comprising different no of rows and columns even sometimes NULL, such as [[2]] given below. How can we ignore [[2]] or others like this in the complete list. Any help in this regard is needed. Thanks
>>
>> [[1]]
>>       [,1] [,2]
>> [1,]    3    1
>> [2,]    3    1
>> [3,]    3    1
>>
>> [[2]]
>> NULL
>>
>> [[3]]
>>        [,1] [,2] [,3] [,4] [,5] [,6] [,7]
>>  [1,]    3    1    0    0    0    0    0
>>  [2,]    3    1    0    0    0    0    0
>>  [3,]    3    1    0    0    0    0    0
>>  [4,]    3    1    3    1    3    2    1
>>  [5,]    3    1    3    1    3    2    1
>>  [6,]    3    1    3    1    3    2    0
>>
>> [[4]]
>>       [,1] [,2] [,3] [,4]
>> [1,]    3    0    0    0
>> [2,]    3    1    3    3
>> [3,]    3    1    3    3
>> [4,]    3    1    3    0
>>
>> OR
>> x1=c(1,2,3); x2=c(1,2,3,4,6); x3=c(); x=list(x1,x2,x3)
>>
>> M.Azam
>>
>>
>>
>>        [[alternative HTML version deleted]]
>>
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>>
> 
> 
>