[R] Introduction of NA:s

[Eric Lecoutre]

You could use the following:

x <- rnorm(10000)
ind <- unlist(matrix(1:10000,byrow=T, ncol=10)[,6:10])
selection <- sample(ind, 500)
x[selection] <- NA


I am pretty sure there is a quicker way to create selection vector...

Eric


At 12:01 2/10/2002 +0200, you wrote:
>Hello,
>
>I wonder if someone could help me with the following: I have generated 10 
>000 values from rnorm and now I want to randomly replace 500 of those with 
>NA. The problem is that values indexed between 6-10,16-20,26-30.... only 
>should be considered for replacement. Any suggestions?
>
>Patrik Waldmann


__________________________________________________

Eric Lecoutre           Informaticien/Statisticien
Institut de Statistique                        UCL

                               (+32) (0)10 47 30 50
                            lecoutre at stat.ucl.ac.be
     http://www.stat.ucl.ac.be/ISpersonnel/lecoutre

__________________________________________________
Le vrai danger, ce n'est pas quand les ordinateurs
penseront comme des hommes, c'est quand les hommes
penseront comme des ordinateurs.     Sydney Harris


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