R help - Sep 2011 - remove NaN from element in a vector in a list

Hello,

What is the best way to turn a matrix into a list removing NaN's? I'm
new to
R...

Start:
> mt = matrix(c(1,4,NaN,5,3,6),2,3)
> mt
     [,1] [,2] [,3]
[1,]    1  NaN    3
[2,]    4    5    6

Desired result:
> lst
[[1]]
[1] 1 3

[[2]]
[1] 4 5 6


Thanks!

Ben

	[[alternative HTML version deleted]]

Try this:

alply(mt, 1, function(x) as.numeric(na.omit(x)))

The as.numeric() addition may be necessary to strip the extra attributes
na.omit() wants to add.

Michael

On Tue, Sep 27, 2011 at 4:02 PM, Ben qant <ccquant@gmail.com> wrote:
> Hello,
>
> What is the best way to turn a matrix into a list removing NaN's?
I'm new
> to
> R...
>
> Start:
>
> > mt = matrix(c(1,4,NaN,5,3,6),2,3)
> > mt
>     [,1] [,2] [,3]
> [1,]    1  NaN    3
> [2,]    4    5    6
>
> Desired result:
>
> > lst
> [[1]]
> [1] 1 3
>
> [[2]]
> [1] 4 5 6
>
>
> Thanks!
>
> Ben
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
	[[alternative HTML version deleted]]

On Sep 27, 2011, at 4:02 PM, Ben qant wrote:
> Hello,
>
> What is the best way to turn a matrix into a list removing NaN's?  
> I'm new to
> R...
>
> Start:
>
>> mt = matrix(c(1,4,NaN,5,3,6),2,3)
>> mt
>     [,1] [,2] [,3]
> [1,]    1  NaN    3
> [2,]    4    5    6
 > apply(mt, 1, function(x) x[!is.nan(x)] )
[[1]]
[1] 1 3

[[2]]
[1] 4 5 6

The function is.finite would also remove infinities as well as the NaNs.

>
> Desired result:
>
>> lst
> [[1]]
> [1] 1 3
>
> [[2]]
> [1] 4 5 6
>
>
> Thanks!
>
David Winsemius, MD
West Hartford, CT

>> apply(mt, 1, function(x) x[!is.nan(x)] )
> [[1]]
> [1] 1 3
>
> [[2]]
> [1] 4 5 6
You need to be a little careful with apply:
> mt2 <- matrix(c(1,4,2,5,3,6),2,3)
> apply(mt2, 1, function(x) x[!is.nan(x)] )
     [,1] [,2]
[1,]    1    4
[2,]    2    5
[3,]    3    6

Depending on the input you will get a list or matrix as output.

Hadley

-- 
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/