Hello,


I have a big problem which I’m just not able to solve.



I created the following mean value from the following dataset structure:


Id |value

1  | 2

1  | 3

1  | 4

2  | 2

2  | 1

3  | 5

4  | 3

etc.|etc.



with the command:

mean_rating <- tapply(ratok$value, ratok$project_id , mean,simplify = FALSE)



this gives me  a ragged array:

> mean_rating [1]

$`14` ###########==project_id

[1] 3.933333 #######==mean value





> dim (mean_rating)

[1] 2214



I want to separate now the project_id from the mean value. So that I have
two separate         columns (2 dimension).



How can I separate a ragged array into two variables?







*Additional information:*

I need this information to put the mean value into another dataset
(“projok”) at the correct project_id.



I would do that as follow:

k=projok[,1]



for(i in 1:2442) {

                projLineNb = which(mean_rating$project_id==k[i])

                projok$mean[i] = mean_rating$value[projLineNb]

}



But with a ragged array I can not refer to project_id. Or is there a
possibility that I can refer to the project_id in a ragged array?



> mean_rating [[1]]

[1] 3.933333 ==I can refer to the value only



Thank you very much

Best,

Helene

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