[R] discrete variable

[(Ted Harding)]

On 02-Mar-08 20:27:20, Pete Dorothy wrote:
> Hello,
> 
> I am sorry for asking such a basic question. I could not find
> an answer to it using google.
> 
> I have a discrete variable (a vector x) taking for example the
> following values : 0, 3, 4, 3, 15, 5, 6, 5
> 
> Is it possible to know how many different values (modalities)
> it takes?
> Here it takes 6 different values but the length of the vector is 8.
> 
> I would like to know if there is a way to get the set of the
> modalities {0,3,4,15,5,6} with the number of times each one is
> taken {1,2,1,1,2,1}

This particulat kind of question is very simple:

table(c(0, 3, 4, 3, 15, 5, 6, 5))
# 0  3  4  5  6 15
# 1  2  1  2  1  1 

Note that the first row of the output is simply the column
names, and is not part of the value returned by table() in
this case, which is the vector c(1,2,1,2,1,1) printed in
the second row.

table(c(0, 3, 4, 3, 15, 5, 6, 5))[4]
# 5 
# 2 

table(c(0, 3, 4, 3, 15, 5, 6, 5))[4] + 1.1
#   5 
# 3.1 

sum(table(c(0, 3, 4, 3, 15, 5, 6, 5)))
# [1] 8

Hoping this helps.

> Thank you very much
> 
> P.S. : is there some useful functions for discrete variables ?

Many!

Ted.

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Date: 02-Mar-08                                       Time: 20:52:40
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