K-Mean Clustering Code is not working

[wklow83]

Hi guys,

I got the codes from online resources, when i run it to do k-means clustering, it seems don't work as it should be (it should be a 6 columns x 4 rows table, but it only returns 5 columns x 3 rows table).

I have data in datasheet (worksheet) in 6 columns x 33 rows table.
Then, i have initial 4 centroids coordinates in activesheet G3:L6.

I want to return the results (new calculated centroid coordinates paste at range G7 as i indicated in the worksheet) by calculating from the datasheet data range (as i indicated int the worksheet too). Below are my parameter in the same activesheet to run the k-means clustering

MaxIt	150
Data Sheet	DataSheet
Data Range	J6:O38
Output Sheet	DataSheet
Output Range	P6
Initial Centr	G3:L6
Output Centr	G7

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I am not a originator of the code, but i would like to learn from code and know how to make it works. the codes are as follows:

Sub kmeans()
'x main macro x'


'x get the initial centroid data


Dim InitCentrRange As String:   InitCentrRange = ActiveSheet.Range("C7").Value
Dim InitialCentroids As Variant: InitialCentroids = ActiveSheet.Range(InitCentrRange)


'x get the number of max iterations


Dim MaxIt As Integer:   MaxIt = ActiveSheet.Range("C2").Value


'x get the features data


Dim DataSht As String: DataSht = ActiveSheet.Range("C3").Value
Dim DataRange As String: DataRange = ActiveSheet.Range("C4").Value
Dim X As Variant: X = Worksheets(DataSht).Range(DataRange)


'x assign objects to centroids based on initial centroids


Dim my_idx As Variant: my_idx = FindClosestCentroid(X, InitialCentroids)


Dim J As Integer:   J = UBound(X, 2) 'number of features
Dim K As Integer:   K = UBound(InitialCentroids, 1) 'number of clusters
Dim M As Integer:   M = UBound(X, 1) 'number of objects


Dim centroids As Variant
Dim ii As Integer: ii = 1
For ii = 1 To MaxIt
    centroids = ComputeCentroids(X, my_idx, K)
    my_idx = FindClosestCentroid(X, centroids)
Next ii


'x print the centroids


Dim outputRange As String:  outputRange = ActiveSheet.Range("C8").Value
Range(outputRange).Resize(K, J).Value = centroids


'x print the cluster assignment next to data


Dim ClusterOutputSht As String: ClusterOutputSht = ActiveSheet.Range("C5").Value
Dim ClusterOutputRange As String: ClusterOutputRange = ActiveSheet.Range("C6").Value
Worksheets(ClusterOutputSht).Range(ClusterOutputRange).Resize(M, 1).Value = WorksheetFunction.Transpose(my_idx)




End Sub

Public Function FindClosestCentroid(ByRef X As Variant, ByRef centroids As Variant) As Variant


'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
'x Function loops through all observations and calculate the distance to all centroids  x'
'x Function then returns an array with all the nearest centroids for each observation   x'
'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'


Dim K As Integer:   K = UBound(centroids, 1)
Dim J As Integer:   J = UBound(centroids, 2)
Dim M As Integer:   M = UBound(X, 1)
Dim idx() As Variant:   ReDim idx(M) As Variant
Dim ii As Integer:  ii = 1
Dim cc As Integer:  cc = 1


'For eahc observation find the closest centroid


For ii = 1 To M
    Dim Dist_min As Double: Dist_min = 1000000
    Dim Dist As Double: Dist = 0
    'for each K calculate the distance
    For cc = 1 To K
        Dist = EuclideanDistance(Application.Index(X, ii, 0), Application.Index(centroids, cc, 0), J)
        If Dist < Dist_min Then
            idx(ii) = cc
            Dist_min = Dist
        End If
    Next cc
Next ii


FindClosestCentroid = idx()


End Function

Public Function ComputeCentroids(X As Variant, idx As Variant, K As Variant) As Variant


'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
'x Function that calculates the new centroid mean for each feature                      x'
'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'


Dim M As Integer:   M = UBound(X, 1) 'number of objects
Dim J As Integer:   J = UBound(X, 2) 'number of features
Dim ii As Integer:  ii = 1
Dim cc As Integer:  cc = 1
Dim bb As Integer:  bb = 1
Dim counter As Integer: counter = 0
Dim centroids() As Variant: ReDim centroids(K, J) As Variant
Dim tempSum() As Variant


For ii = 1 To K 'for each centroid
    For bb = 1 To J 'for each feature
        counter = 0 'reset counter
        For cc = 1 To M 'for each observation
            If idx(cc) = ii Then 'for objects that below to this centroid calc the sum
                centroids(ii, bb) = centroids(ii, bb) + X(cc, bb)
                counter = counter + 1
            End If
        Next cc
        If counter > 0 Then     'modified
        centroids(ii, bb) = centroids(ii, bb) / counter 'divide sum by counter to get mean
        Else                    'modified
        centroids(ii, bb) = 0   'modified
        End If                  'modified
    Next bb
Next ii


ComputeCentroids = centroids


End Function

Public Function EuclideanDistance(X As Variant, Y As Variant, num_obs As Integer) As Double


'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
'x Function that calculates the euclidean distance between two vectors of size num_obs each    x'
'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'


Dim ii As Integer: ii = 1
Dim RunningSumSqr As Double: RunningSumSqr = 0
For ii = 1 To num_obs
    RunningSumSqr = RunningSumSqr + (X(ii) - Y(ii)) ^ 2
Next ii


EuclideanDistance = Sqr(RunningSumSqr)


End Function

I appreciate any help that i could have. Thank you in advance!


Thanks in advance,
Wye