[R] Split a list

[David Winsemius]

On Oct 14, 2011, at 9:26 AM, Weidong Gu wrote:

> It would be nice if you could provide a sample.

That is certainly true.

> However, if the data
> in the list have the same colnames, you can combine them by
>
> df<-do.call('rbind',your_list_data_frame)
>
> Then you can do what you want on the dataframe instead of a list
>
> HTH
>
> Weidong Gu
>
>
> On Fri, Oct 14, 2011 at 9:06 AM, Juliet Ndukum <jpntsang at yahoo.com>  
> wrote:
>> I have a list of dataframes i.e. each list element is a dataframe  
>> with three columns and differing number of rows. The third column  
>> takes on only two values. I wish to split the list into two  
>> sublists based on the value of the third column of the list element.

Perhaps something like:
list_of_firsts <- lapply(dflist, function(x) X[ , X[,3]=="first"] )
list_of_seconds <- lapply( dflist, function(x) X[ , X[,3]=="second"])

Ow with subset (but without that missing example it is more difficult  
to show the true value of subset:

subset(X, select= X[,3]=="first")


>> Second issue with lists as well. I would like to reduce each of the  
>> sublist based on the range of the second column, i.e. if the range  
>> of the second column is greater than twenty for example keep the  
>> list element.

Same as above with an inequality sign.

>>
>> Could someone help me with a code to implement these two issues.  
>> Thanks in advance for your help,
>> JN
>>        [[alternative HTML version deleted]]
>


David Winsemius, MD
West Hartford, CT