# [R] finding the most frequent row

bogdan romocea br44114 at yahoo.com
Fri Dec 10 14:53:36 CET 2004

```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

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