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copied!<p>This is one possible solution [untested]. The <code>AddNearestColumn()</code> method loops through each row and gets a List of distances to the other points in the table. It then loops through the list and gets the smallest value. You should use <code>distances.Sort()</code> in <code>AddNearestColumn()</code> rather than looping manually, but I'll leave that for you. :-)</p> <pre><code>Public Sub ProcessTable(table As Data.DataTable) AddNearestColumn(table) End Sub Private Sub AddNearestColumn(table As Data.DataTable) table.Columns.Add("Nearest", GetType(Double)) For Each r As Data.DataRow In table.Rows Dim distances As List(Of Double) = GetDistancesFromPoint(table, r) Dim nearest As Double = Double.MaxValue For Each distance As Double In distances If (distance < nearest) Then nearest = distance Next r.Item("Nearest") = nearest Next End Sub Private Function GetDistancesFromPoint(table As Data.DataTable, referenceRow As Data.DataRow) As List(Of Double) Dim output As New List(Of Double) For Each r As Data.DataRow In table.Rows Dim referenceId As String = CStr(referenceRow.Item("ID")) Dim rowId As String = CStr(r.Item("ID")) If (rowId = referenceId) Then Continue For Dim x1 As Double = Convert.ToDouble(referenceRow.Item("X")) Dim y1 As Double = Convert.ToDouble(referenceRow.Item("Y")) Dim x2 As Double = Convert.ToDouble(r.Item("X")) Dim y2 As Double = Convert.ToDouble(r.Item("Y")) output.Add(Math.Sqrt(((x2 - x1) * (x2 - x1)) + ((y2 - y1) * (y2 - y1)))) Next Return output End Function </code></pre>

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