[R] select most frequent value in set of variables

[PIKAL Petr]

Hi

It is really a typical example of a question which has probably very simple solution but hardly anybody can give you a rasonable answer.

How your data look like?
What is the structure of your data?

set.seed(1)
x<-sample(1:4, 60, replace=T)
mat<-as.factor(x)
dim(mat) <- c(20,3)

> sapply(apply(mat,1, table), max)
 [1] 2 1 2 1 1 2 2 2 2 1 2 1 2 2 2 1 1 1 2 2
> names(sapply(apply(mat,1, table), which.max))
 [1] "4" "1" "3" "1" "1" "4" "1" "2" "3" "1" "2" "1" "2" "1" "4" "1" "2" "1" "3"
[20] "2"

gives you the most frequent value in each row of matrix mat.

Petr


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Sam Dekeyser
> Sent: Monday, August 20, 2012 10:48 AM
> To: r-help at r-project.org
> Subject: [R] select most frequent value in set of variables
> 
> Hi,
> 
> I would like to select the most frequent value level in a set of three
> variables.
> 
> Three different observators have judged hair color in study subjects.
> Mostly they judge the same color, sometimes there is a slight
> difference. I want to know what most of the observators have chosen (so
> at least 2) from the 3 observations. E.g. If two out of three
> observators decide the hair is black, then it's likely not to be brown.
> 
> Let's say that i have 3 variables: color1, color2, color3. Each have 4
> possible levels (fair up to black, 1-4). I would like a new variable
> containing this 'most frequent judgement'.
> 
> I have already searched through the knowledge base and many posts but I
> haven't found what I'm looking for.
> 
> Is this possible?
> 
> Thank you in advance!
> Sam
> 
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