Remove NA from list of lists

Amberopolis picture Amberopolis · Sep 11, 2014 · Viewed 28.8k times · Source

I have a matrix, data.mat, that looks like:

A B C D E  
45 43 45 65 23   
12 45 56 NA NA   
13 4  34 12 NA  

I am trying to turn this into a list of lists, where each row is one list within a bigger list. I do the following:

list <- tapply(data.mat,rep(1:nrow(data.mat),ncol(data.mat)),function(i)i)

which gives me a list of lists, with NAs included, such as:

$`1`  
 [1]  45 43 45 65 23  
$`2`  
 [1]  12 45 56 NA NA  
$`3`  
 [1]  13 4 34 12 NA  

But what I want is:

$`1`  
 [1]  45 43 45 65 23  
$`2`  
 [1]  12 45 56   
$`3`  
 [1]  13 4 34 12   

Is there a good way to remove the NAs either during the tapply call or after the fact?

Answer

rsoren picture rsoren · Sep 11, 2014

Sure, you can use lapply like this:

> lapply(list, function(x) x[!is.na(x)])
$`1`
[1] 45 43 45 65 23

$`2`
[1] 12 45 56

$`3`
[1] 13  4 34 12