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I'll explain my problem using an example with the iris table. Let's say I want to create a tree between sepal width and species. For this I will use this code:

ctree(Species~Sepal.Width,data=iris)->a
plot(a,type="simple")

The problem is that, if I want to do a data frame, for example counting the quantity of cases in each node (from 0 to 2.9; 2.9 to 3.3, etc), the only way I've found to do this is by creating a new vector manually and then using the dcast or table function.

The problem with this solution is that if I had a bigger tree result, it could be quite difficult. Do you know any other solution for this? Thanks a lot.

Mihai Chelaru
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vero
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1 Answers1

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Actually, the party structure created by ctree has that information stored in it. Using your example, a[1]$fitted[,1] has which leaf each point ended up in. So you can get the number of points at each leaf with:

table(a[1]$fitted[,1])
 3  4  5 
57 56 37

If you are trying to see the rules that go with the leaf numbers, you can use:

partykit:::.list.rules.party(a)
                                        3 
"Sepal.Width <= 3.3 & Sepal.Width <= 2.9" 
                                        4 
 "Sepal.Width <= 3.3 & Sepal.Width > 2.9" 
                                        5 
                      "Sepal.Width > 3.3"
G5W
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  • Hello, if I execute a[1]$fitted[,1], I obtain this error:Error in a[1] : object of type 'S4' is not subsettable. Do you know how can I fix it? – vero Dec 28 '18 at 18:18
  • When I execute your code above, then execute my code, I get no error. when I run `class(a)` I get `[1] "constparty" "party"` What do you get? – G5W Dec 28 '18 at 18:48
  • I get [1] "BinaryTree" attr(,"package") [1] "party – vero Jan 02 '19 at 18:08