Re: [R] summary statistics for lists of matrices or dataframes

From: Patrick Burns <pburns_at_pburns.seanet.com>
Date: Wed 11 May 2005 - 00:49:38 EST

You could use 'do.call' with 'bind.array' (from S Poetry) or 'abind' to convert your list of matrices into a three-dimensional array.

Patrick Burns

Burns Statistics
patrick@burns-stat.com
+44 (0)20 8525 0696
http://www.burns-stat.com
(home of S Poetry and "A Guide for the Unwilling S User")

David Kane wrote:

>Is there a simple way to calculate summary statistics for all the
>matrices or dataframes in a list? For example:
>
>
>
>>z <- list(matrix(c(2,2,2,2), ncol = 2), matrix(c(4,4,4,4), ncol = 2))
>>z
>>
>>
>[[1]]
> [,1] [,2]
>[1,] 2 2
>[2,] 2 2
>
>[[2]]
> [,1] [,2]
>[1,] 4 4
>[2,] 4 4
>
>
>
>I would like to calculate, for example, the mean value for each
>cell. I can do that the hard way as:
>
>
>
>>(z[[1]] + z[[2]]) / 2
>>
>>
> [,1] [,2]
>[1,] 3 3
>[2,] 3 3
>
>
>
>But there must be an easier way. I am also interested in other
>statistics (like median and sd). Since all my matrices have the same
>attributes (especially row and column names), I would like to preserve
>those in the answer.
>
>Thanks,
>
>Dave Kane
>
>In case it matters:
>
>
>
>>R.version
>>
>>
> _
>platform i686-pc-linux-gnu
>arch i686
>os linux-gnu
>system i686, linux-gnu
>status
>major 2
>minor 1.0
>year 2005
>month 04
>day 18
>language R
>
>
>
>______________________________________________
>R-help@stat.math.ethz.ch mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>
>
>
>
>



R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Wed May 11 00:56:12 2005

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