Converting A 'List of Lists' to a Datatree structure in VB

An engineer friend of mine has been giving me a hand with VB coding a custom component for grasshopper. The final output looks like this;

1: System.Collections.Generic.List`1[Rhino.Geometry.Point3d]
2: System.Collections.Generic.List`1[Rhino.Geometry.Point3d]
3: System.Collections.Generic.List`1[Rhino.Geometry.Point3d]

etc

I suspect this is because he wasn't aware of the DataTree structure inside grasshopper and just stored the final outputs as a list of lists, as below;

Dim allConnections As New List(Of List(Of Point3d)) 'Retrieve the list of all of the connections (now culled)
    For Each vertex As MyVertex In vertexList
      allConnections.Add(vertex.GetConnections)
    Next

    connectionListList = allConnections

Is there a quick way to convert this into a DataTree structure?
Cheers

Replies to This Discussion

Permalink Reply by Andrew Heumann on January 21, 2013 at 7:51pm

Here is a hacky way -

If you create an additional scripting component with one input "x" set to Item Access, and then write the following script:

A = x

It should actually output a data tree with each list in its own branch.

Otherwise, you'll need to actually write a function to populate a data tree. Here's a function in C#:

static DataTree<T> ListOfListsToTree<T>(List<List<T>> listofLists){
DataTree<T> tree = new DataTree<T>();
for(int i = 0;i < listofLists.Count;i++){
tree.AddRange(listofLists[i], new GH_Path(i));
}
return tree;
}

Permalink Reply by Chris Welch on January 22, 2013 at 2:41pm

The hack way worked perfectly, and I ain't fussy - cheers man!

Permalink Reply by Austin Herrema on October 31, 2014 at 3:05pm

Hey Andrew,

I see you posted this a while ago (so hopefully you'll respond!), but I'm interested in utilizing the C# function you've defined here. However, I'm fairly new to C# and scripting and could use a little help regarding the particulars of how this is used.

Would I be correct that one should place the function in the "<custom additional code>" segment at the bottom of the scripting environment? If so, what is the syntax that should be used in the main body of the script to access said function?

Thanks in advance (if you see this!),

Austin

Permalink Reply by max enko on November 7, 2014 at 3:37pm

Austin, here is an example.

http://codepaste.net/eqdo22

Permalink Reply by Austin Herrema on November 10, 2014 at 7:50am

Perfectly clear, thank you!

Permalink Reply by max enko on November 7, 2014 at 3:35pm

Was about to task same question. Thank you!

Permalink Reply by Giulio Piacentino on January 8, 2015 at 2:55am

Here

is a similar concept, written in Python, to transform arbitrarily-deep trees to arbitrarily nested lists. I am linking this here to help people find it.

Giulio
--
Giulio Piacentino
for Robert McNeel & Associates
giulio@mcneel.com

Permalink Reply by pepe ballesteros on June 14, 2017 at 3:34am