R help - Dec 2004 - finding the most frequent row

I am bootstrapping using a function that I have defined.  The
"Statistic" of the function is an array of 10 numbers.  Therefore if I
use 1000 replications,  the "t" matrix will have 1000 rows each of
which is a bootstrap replicate of this 10 number array (10 columns).  Is there
any easy way in R to determine which row appears the most frequently?

Thanks,
Lisa Pappas

Huntsman Cancer Institute wishes to promote open communication while protecting
confidential and/or privileged information.  If you have received this message
in error, please inform the sender and delete all copies.

Here's something that works. I'm sure there are better solutions (in
particular the paste part - I couldn't figure out how to avoid typing
a[i,1], ..., a[i,10]).

a <- matrix(nrow=1000,ncol=10)
for (i in 1:1000)
	for (j in 1:10)
		a[i,j] <- sample(1:0,1)

b <- vector(mode="character")
for (i in 1:1000)
	b[i] <- paste(a[i,1],a[i,2],a[i,3],a[i,4],a[i,5],
		a[i,6],a[i,7],a[i,8],a[i,9],a[i,10],sep="")

#the most frequent row
table(b)[table(b) == max(table(b))]

HTH,
b.


-----Original Message-----
From: Lisa Pappas [mailto:lisa.pappas at hci.utah.edu]
Sent: Thursday, December 09, 2004 5:15 PM
To: r-help at stat.math.ethz.ch
Subject: [R] finding the most frequent row


I am bootstrapping using a function that I have defined.  The
"Statistic" of the function is an array of 10 numbers.  Therefore if
I use 1000 replications,  the "t" matrix will have 1000 rows each of
which is a bootstrap replicate of this 10 number array (10 columns). 
Is there any easy way in R to determine which row appears the most
frequently? 

Thanks,
Lisa Pappas

Huntsman Cancer Institute wishes to promote open communication while
protecting confidential and/or privileged information.  If you have
received this message in error, please inform the sender and delete
all copies.

______________________________________________
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

> From: Kjetil Brinchmann Halvorsen
> 
> bogdan romocea wrote:
> 
> >Here's something that works. I'm sure there are better
solutions (in
> >particular the paste part - I couldn't figure out how to avoid
typing
> >a[i,1], ..., a[i,10]).
> >
> >a <- matrix(nrow=1000,ncol=10)
> >for (i in 1:1000)
> >	for (j in 1:10)
> >		a[i,j] <- sample(1:0,1)
> >
> >b <- vector(mode="character")
> >for (i in 1:1000)
> >	b[i] <- paste(a[i,1],a[i,2],a[i,3],a[i,4],a[i,5],
> >		a[i,6],a[i,7],a[i,8],a[i,9],a[i,10],sep="")
> >  
> >
> Or
> 
> b <- apply(a, 1, function(x) paste(x, sep="",
collapse=""))
Or, as Peter pointed out recently:

  b <- apply(a, 1, paste, sep="", collapse="")

Andy
 
> Kjetil
> 
> >#the most frequent row
> >table(b)[table(b) == max(table(b))]
> >
> >HTH,
> >b.
> >
> >
> >-----Original Message-----
> >From: Lisa Pappas [mailto:lisa.pappas at hci.utah.edu]
> >Sent: Thursday, December 09, 2004 5:15 PM
> >To: r-help at stat.math.ethz.ch
> >Subject: [R] finding the most frequent row
> >
> >
> >I am bootstrapping using a function that I have defined.  The
> >"Statistic" of the function is an array of 10 numbers. 
Therefore if
> >I use 1000 replications,  the "t" matrix will have 1000 rows
each of
> >which is a bootstrap replicate of this 10 number array (10 columns). 
> >Is there any easy way in R to determine which row appears the most
> >frequently? 
> >
> >Thanks,
> >Lisa Pappas
> >
> >Huntsman Cancer Institute wishes to promote open communication while
> >protecting confidential and/or privileged information.  If you have
> >received this message in error, please inform the sender and delete
> >all copies.
> >
> >______________________________________________
> >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
> >
> >______________________________________________
> >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
> >
> >
> >  
> >
> 
> 
> -- 
> 
> 
> Kjetil Halvorsen.
> 
> Peace is the most effective weapon of mass construction.
>                --  Mahdi Elmandjra
> 
> ______________________________________________
> 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
> 
>