Using DataTree - help and/or resources

I've searched this forum a little and found a few helpful tips, but I'm still struggling creating a data tree in my VB component.

Here's what I have so far:

Private Sub RunScript(ByVal sortedNumberList As List(Of Double), ByVal tolerance As Double, ByRef binnedList As Object)

Dim numberOfBins As Integer
Dim binLimitsList As New List(Of Double)
Dim limit As Double
Dim sortedNumber As Double
Dim binLimit As Double
Dim bin As New List(Of Object)
Dim bucketCounter As Integer
Dim min : min = sortedNumberList(0)
Dim max : max = sortedNumberList(sortedNumberList.Count - 1)
numberOfBins = Math.Floor((max - min) / tolerance)
Call Print("numberOfBins = " & numberOfBins)
'Dim bucketOfBins As New List(Of List(Of Double))(numberOfBins)
Dim bucketOfBins As New DataTree(Of Object)
limit = Math.Floor(min) + tolerance
'Create list of bin limits
Dim i As Integer
For i = 0 To numberOfBins
binLimitsList.Add(limit)
'Call Print(limit)
limit = limit + tolerance
Next
Call Print("Bin : Number")
For Each sortedNumber In sortedNumberList
bucketCounter = 0
For Each binLimit In binLimitsList
If (sortedNumber < binLimit) Then
Call Print(" " & CStr(bucketCounter) & " : " & CStr(sortedNumber))
'bucketOfBins(bucketCounter).Add(sortedNumber)
bin.Add(sortedNumber)
bucketOfBins.Add(bin, New GH_Path(bucketCounter))
Exit For
End If
bucketCounter = bucketCounter + 1
Next
Next
binnedList = bucketOfBins
End Sub

I'm specifically struggling with line 42:

bucketOfBins.Add(bin, New GH_Path(bucketCounter))

I declared buckOfBins on line 17:

Dim bucketOfBins As New DataTree(Of Object)

From the readout on the "out" output of the VB component, the script is working as I intended, grouping the numbers in the list into bins. And the return value on line 53 is a data tree with the correct branching structure, but instead of the numbers in the lists, it says:

System.Collections.Generic.List`1[System.Object]

Any help would be appreciated. Also, any better resources for learning VB.NET specifically for Grasshopper rather than the Grasshopper Primer would be appreciated as well.

Attachments:

140613_BinSort.gh, 10 KB

Replies to This Discussion

Permalink Reply by Damon on June 16, 2014 at 2:20pm

Can anybody help?

Permalink Reply by David Rutten on June 16, 2014 at 3:52pm

You're adding List(Of Object) to the datatree, that's why it fails.

I rewrote your script, it now works on non-sorted numbers and it can handle multiple lists of numbers:

Private Sub RunScript(ByVal Numbers As List(Of Double), ByVal Tolerance As Double, ByRef Bins As Object)
If (Numbers.Count = 0) Then Return

Dim sortedNumbers As New List(Of Double)(Numbers)
sortedNumbers.Sort()

Dim min = sortedNumbers(0)
Dim max = sortedNumbers(sortedNumbers.Count - 1)

Dim binCount As Integer = Convert.ToInt32(Math.Floor((max - min) / Tolerance))
Print("binCount = " & binCount)

Dim binBoundaries As New List(Of Double)
For i As Integer = 1 To binCount
binBoundaries.Add(min + i * Tolerance)
Next

Print("Bin : Number")
Dim binTree As New DataTree(Of Double)
For Each number As Double In Numbers
Dim binIndex As Int32 = 0
For Each boundary As Double In binBoundaries
If (number < boundary) Then
Print(" {0} : {1}", binIndex, number)
binTree.Add(number, New GH_Path(Iteration, binIndex))
Exit For
End If

binIndex += 1
Next
Next

Bins = binTree
End Sub

David Rutten

david@mcneel.com

Attachments:

140613_BinSort.gh, 9 KB

Permalink Reply by Damon on June 17, 2014 at 9:19am

David,

Thank you so much. It is great to have a working bin sort. FYI, it drops the last number in the list.

Would you help me understand this line?

binTree.Add(number, New GH_Path(Iteration, binIndex))

I get that you are adding the number to the data tree, but I don't understand the New GH_Path(Iteration, binIndex) part. I'm reading the SDK help file and I understand that the GH_Path Class is the structure or path of a item or list of items. However, more explanation would really help. I don't understand the Iteration Property or how you are using it.

Thanks,

Damon

Permalink Reply by David Rutten on June 17, 2014 at 9:37am

A GH_Path is an array of integers, since I use two integers in the constructor, we'll end up with paths that have two parts; {0;0} instead of just {0}

The Integer value is a member variable of the class itself (it gets set by Grasshopper). Every time the RunScript method is called, the Iteration value will be one higher. Then it gets reset whenever a new solution starts.

By including the Iteration in the paths, I make sure that the datatree I create inside RunScript() doesn't overlap with a previous one, which makes the script capable of running multiple times.

As for the dropped value, perhaps you should add double.MaxValue to the binBoundaries list, just to ensure all possible values are always included. I haven't actually tested this fix though.

David Rutten

david@mcneel.com

Permalink Reply by Damon on June 17, 2014 at 9:51am

David,

Thank you again. So if I understand correctly, by using GH_Path with two integers--Iteration and binIndex--I could run this on data with more than one branch and it would be OK.

I'll look into the binBoundaries list. Thank you.

Best,

Damon

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