[R] selecting rows with more than x occurrences in a given column(data type is names)

[Dimitris Rizopoulos]

try this:

set.seed(123)
all.data <- data.frame(name = sample(c("Joe", "Elen", "Jane", "Mike"), 
8, TRUE),
    x = rnorm(8), y = runif(8))
##########
tab.nams <- table(all.data$name)
nams <- names(tab.nams[tab.nams >= 2])
all.data[all.data$name %in% nams, ]


I hope it helps.

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


----- Original Message ----- 
From: "Mike Jasper" <mikejjasper at gmail.com>
To: <r-help at stat.math.ethz.ch>
Sent: Tuesday, March 13, 2007 3:38 PM
Subject: [R] selecting rows with more than x occurrences in a given 
column(data type is names)


> Despite a long search on the archives, I couldn't find how to do 
> this.
> Thanks in advance for what is likely a simple issue.
>
> I have a data set where the first column is name (i.e., 'Joe Smith',
> 'Jane Doe', etc). The following columns are data associated with 
> that
> person. I have many people with multiple rows. What I want is to get 
> a
> new data frame out with only the people who have more than x
> occurrences in the first column.
>
> Here's what I've done, that's not working:
>
> Let's call my old data.frame "all.data"
>
> table(all.data$names)>10
>
> I get a list of names and TRUE/FALSE values. I then want to make a
> list of the TRUEs and pass that to some subset type command like
>
> dup.names=table(all.data$names)>10
>
> new.data=(all.data[all.data$names==dup.names,])
>
> That's not working because the dimensions are wrong (I think). But
> even when I tried to do part of it manually (to troubleshoot) like
> this
>
> dup.names=c('Joe Smith','Jane Doe','etc')
>
> I got warnings and it didn't work correctly. There must be a simple
> way to do this that I'm just not seeing. Thanks.
>
> ______________________________________________
> R-help at 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
> and provide commented, minimal, self-contained, reproducible code.
> 


Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm