[R] Simple 'frequency' function?

[Uwe Ligges]

Dan Bolser wrote:

> Hi, I have designed the following function to extract count frequencies
> from an array of integers. For example...
> 
> # Tipical array
> x <- cbind(1,1,1,1,1,2,2,2,2,3,3,3,3,4,5,6,7,22)
> 
> # Define the frequency function
> frequency <-
>   function(x){
>     max <- max(x)
>     j <- c()
>     for(i in 1:max){
>       j[i] <- length(x[x==i])
>     }
>     return(j)
> }
> 
> fre <- frequency(x)
> plot(fre)
> 
> How can I ... 
> 
> 1) Make this a general function so my array could be of the form
> 
> # eats!
> x <- cbind( "egg","egg","egg","egg","ham","ham","ham","ham","chicken" )
> 
> fre <- frequency(x)
> plot(fre)
> 
> 2) Make frequency return an object which I can call plot on (allowing the
> prob=TRUE option).


See ?table:

   table(x)
   plot(table(x))
   plot(table(x) / sum(table(x)))

Uwe Ligges



> Cheers,
> Dan.
> 
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