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create new variable in dataset from combinations of other variables

4 vues (au cours des 30 derniers jours)
jonas
jonas le 14 Mar 2013
Hi I have a problem regarding creating a new variable in a dataset array and assign it a value from information in the dataset Here is a simplified version of my dataset:
variables a b c observation [j k v; j r v; i r s; i k s; j k v; j k v]
I want to add a new variable and assign it a value depending on the combination of the variables a,b and c. So for example the combinations in a b c j k v = 1, j r v = 2,i r s = 3, i k s = 4 So for this short example I want to add a new variable to the dataset with the values 1,2,3,4,1,1
Final result should be: variables a b c d observation [j k v 1; j r v 2 ; i r s 3 ; i k s 4; j k v 1 ; j k v 1 ]
It's a large dataset but this illustrates what i want to do.
Help please?

Réponse acceptée

Peter Perkins
Peter Perkins le 15 Mar 2013
Create a vector of length 4 with the values you want, and assign
d.GroupIndex = values(i)
instead.
  2 commentaires
jonas
jonas le 15 Mar 2013
Great !! Thank you Peter
jonas
jonas le 15 Mar 2013
Just noticed for my large dataset that the value vector has to be of equal length as the i vector...How can I code this? Say that the i vector has a length of 1000 and the values a want to assign is of 4 unique values as in my example..

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Plus de réponses (1)

Peter Perkins
Peter Perkins le 14 Mar 2013
Jonas, I think this is what you're looking for:
d = cell2dataset({'a' 'b' 'c'; 'j' 'k' 'v'; 'j' 'r' 'v'; 'i' 'r' 's'; 'i' 'k' 's'; 'j' 'k' 'v'; 'j' 'k' 'v'})
[~,~,i] = unique(d,[],'stable');
d.GroupIndex = i
  1 commentaire
jonas
jonas le 15 Mar 2013
Thank you Peter! That really helped me. Do you also have an answer how to assign a specific value to the unique rows in your code? For example I want the last column (i) to contain specific values, so the 1 in i should be 2.1, the 2= 6.5 the 3 = 4.2 and the 4 7.9..... BR Jonas

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