R help - Jul 2004 - Simple 'frequency' function?

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.
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html

I think:

frequency <- function(x) table(as.factor(x))

should work generally.  Not sure what you mean by the plotting.

-roger

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).
> 
> Cheers,
> Dan.
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>

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).

Cheers,
Dan.