how to replace some objects?

I want to replace some objects in one row or column.For example,
One colume: a,b,a,c,b,b,a,a,c.
I want to replace "a" with "1", "b" with "2", and "c" with "3".
Like this: 1,2,1,3,2,2,1,1,3.

How to do it? I donot know how to do it. Thanks.

	[[alternative HTML version deleted]]

The example is simply.But the other example:
One column: acba,coma,acmo,acmo,acba,coma
I want to replace "acba" with "aaa", "coma" with "bbb", and "acmo" with 
"ddd".
Like this: aaa,bbb,ddd,ddd,aaa,bbb
How to do it?
Thanks.

 
On 12/19/06, *Jacques VESLOT* <jacques.veslot at good.ibl.fr 
<mailto:jacques.veslot at good.ibl.fr>> wrote:

    you can use as.numeric(factor( )); in your example:

     > ex <- sample(letters[1:3], 10, T)
     > ex

    [1] "b" "b" "c" "b" "a" "a" "b" "b" "a" "a"

     > as.numeric(factor(ex))

    [1] 2 2 3 2 1 1 2 2 1 1

    if the order is different, use levels:

     > as.numeric(factor(ex, levels=letters[3:1]))

    [1] 2 2 1 2 3 3 2 2 3 3

    -------------------------------------------------------------------
    Jacques VESLOT

    CNRS UMR 8090
    I.B.L (2?me ?tage)
    1 rue du Professeur Calmette
    B.P. 245
    59019 Lille Cedex

    Tel : 33 (0)3.20.87.10.44
    Fax : 33 (0)3.20.87.10.31

    http://www-good.ibl.fr
    -------------------------------------------------------------------

    Zhang Jian a ?crit :

     > I want to replace some objects in one row or column.For example,
     > One colume: a,b,a,c,b,b,a,a,c.
     > I want to replace "a" with "1", "b" with "2", and "c" with "3".
     > Like this: 1,2,1,3,2,2,1,1,3.
     >
     > How to do it? I donot know how to do it. Thanks.
     >
     >       [[alternative HTML version deleted]]
     >
     > ______________________________________________
     > R-help at stat.math.ethz.ch <mailto:R-help at stat.math.ethz.ch>

    mailing list

     > https://stat.ethz.ch/mailman/listinfo/r-help
     > PLEASE do read the posting guide

I want to replace some objects in one row or column.For example,
One colume: a,b,a,c,b,b,a,a,c.
I want to replace "a" with "1", "b" with "2", and "c" with "3".
Like this: 1,2,1,3,2,2,1,1,3.

On Dec 19, 2006, at 3:05 AM, Zhang Jian wrote:

I want to replace some objects in one row or column.For example,
One colume: a,b,a,c,b,b,a,a,c.
I want to replace "a" with "1", "b" with "2", and "c" with "3".
Like this: 1,2,1,3,2,2,1,1,3.

let <- c('a', 'b', 'a', 'c', 'b', 'b', 'a', 'a', 'c')
library(car)
num <- recode(let, " 'a' = 1; 'b' = 2; else = 3 ")

as.numeric(factor(let))