Re: [R] Replace missing values in lapply

From: Dimitris Rizopoulos <dimitris.rizopoulos_at_med.kuleuven.be>
Date: Wed 24 Jan 2007 - 15:48:37 GMT

you need to return x in the function within lapply(), e.g., something like

lapply(TP, function(x) { x[is.na(x)] <- 0; x })

I hope it works.

Best,
Dimitris



Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium

Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm



>I have some matrices stored as elements in a list that I am working
> with. On example is provided below as TP[[18]]
>
>> TP[[18]]
> level2
> level1 1 2 3 4
> 1 79 0 0 0
> 2 0 0 0 0
> 3 0 0 0 0
> 4 0 0 0 0
>
> Now, using prop.table on this gives
>
>> prop.table(TP[[18]],1)
> level2
> level1 1 2 3 4
> 1 1 0 0 0
> 2
> 3
> 4
>
> It is important for the zero's to retain their position as this
> matrix
> will subsequently be used in some matrix multiplication and hence,
> must
> be of dimension 4 by 4 so that is it conformable for multiplcation
> with
> another matrix.
>
> In looking at the structure of the object resulting from prop.table
> I
> see NaNs, and so I can do this
>
>> rr <- TP[[18]]
>> rr[is.na(rr)] <- 0
>> rr
> level2
> level1 1 2 3 4
> 1 79 0 0 0
> 2 0 0 0 0
> 3 0 0 0 0
> 4 0 0 0 0
>
> This is exactly what I want for each matrix. But, I have multiple
> matrices stored within the list that need to be changed and so I am
> trying to resolve this via lapply, but something is awry (namely the
> user), but I could use a little help.
>
> I was thinking the following function should work, but it doesn't.
> It
> reduces each matrix within the list to a 0.
>
> PP <- lapply(TP, function(x) x[is.na(x)] <- 0)
>
> Am I missing something obvious?
>
> Harold
>
>
> [[alternative HTML version deleted]]
>
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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. Received on Thu Jan 25 15:00:34 2007

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