Re: [R] counts of each column that are not NA, and/or greater than column means

From: Patrick Burns <pburns_at_pburns.seanet.com>
Date: Mon, 04 Feb 2008 19:34:36 +0000

Gabor Csardi wrote:

>On Mon, Feb 04, 2008 at 03:21:10PM +0800, Ng Stanley wrote:
>
>
>>Hi,
>>
>>Given a test matrix, test <- matrix(c(1,2,3,NA,2,3,NA,NA,2), 3,3)
>>
>>A) How to compute the counts of each column (excluding the NA) i.e., 3, 2, 1
>>
>>
>
>apply(test, 2, function(x) sum(!is.na(x)))
>
>

or more efficiently:

colSums(!is.na(test))

Patrick Burns
patrick_at_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")

>
>
>>B) How to compute the counts of each column (excluding the NA) that are
>>greater than the column means ? i.e., 1, 1, 0
>>
>>
>
>apply(test, 2, function(x) sum(x > mean(x, na.rm=TRUE), na.rm=TRUE))
>
>In general, you need ?apply to calculate something for each row/column
>of a matrix.
>
>Gabor
>
>
>
>>I could write a for loop, but hope to use better alternative.
>>
>> [[alternative HTML version deleted]]
>>
>>______________________________________________
>>R-help_at_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.
>>
>>
>
>
>



R-help_at_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. Received on Mon 04 Feb 2008 - 19:37:10 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Mon 04 Feb 2008 - 20:30:11 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive