[R] Count cell Count by her frequency

David L Carlson dcarlson at tamu.edu
Mon Dec 10 18:44:37 CET 2012


And a third way to interpret the question!

Rui – count rows per category in - A = 3 rows, 1 row, 1 row
David – count different letters used in B per category 
    in A – 3 (a,b,c),  1 (v),  1 (g)
Felipe - count different strings in B per category - 3 (aaa, 
    bbb, abc), 1 (vvv), 1 (ggg)

Interesting that the sample data provide the same answer to all
three questions, but Felipe's interpretation makes more sense 
than mine.

----------------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77843-4352


From: Felipe Carrillo [mailto:mazatlanmexico at yahoo.com] 
Sent: Monday, December 10, 2012 10:05 AM
To: dcarlson at tamu.edu; 'Mat'; r-help at r-project.org
Subject: Re: [R] Count cell Count by her frequency

And another way:
library(plyr)
ddply(dta,"A",summarise,B=length(B))
 
Felipe D. Carrillo
Supervisory Fishery Biologist
Department of the Interior
US Fish & Wildlife Service
California, USA
http://www.fws.gov/redbluff/rbdd_jsmp.aspx

From: David L Carlson <dcarlson at tamu.edu>
To: 'Mat' <matthias.weber at fnt.de>; r-help at r-project.org 
Sent: Monday, December 10, 2012 7:43 AM
Subject: Re: [R] Count cell Count by her frequency

You request is not completely clear. I am assuming you want to count the
number of different characters in B for each category in A:

> A <- c("10-1", "10-1", "10-1", "10-2", "10-3")
> B <- c("aaa", "bbb", "abc", "vvv", "ggg")
> dta <- data.frame(A, B)
> dta
    A  B
1 10-1 aaa
2 10-1 bbb
3 10-1 abc
4 10-2 vvv
5 10-3 ggg
> a1 <- tapply(dta$B, dta$A, paste0, collapse="")
> a2 <- strsplit(a1, "")
> a3 <- lapply(a2, unique)
> a4 <- sapply(a3, length)
> dtanew <- data.frame(A=names(a4), B=a4, row.names=1:length(a4))
> dtanew
    A B
1 10-1 3
2 10-2 1
3 10-3 1

----------------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77843-4352

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Mat
> Sent: Monday, December 10, 2012 2:50 AM
> To: r-help at r-project.org
> Subject: [R] Count cell Count by her frequency
> 
> Hello togehter, i have a data.frame, with value like this:
> 
>        A      B
> 1    10-1  aaa
> 2    10-1  bbb
> 3    10-1  abc
> 4    10-2  vvv
> 5    10-3  ggg
> 
> I want now a evaluation, which character is how often in my data.frame.
> Like
> this one:
>      A        B
> 1  10-1  3
> 2  10-2  1
> 3  10-3  1
> 
> How can i do this?
> 
> Thank you.
> 
> Mat
> 
> 
> 
> --
> View this message in context: http://r.789695.n4.nabble.com/Count-cell-
> Count-by-her-frequency-tp4652650.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> 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.




More information about the R-help mailing list