'Columns Bezeichnung aus meiner typisierten Datatable 'Stoerungen'
 
        With dt.Columns
            .Add("ID", GetType(Integer))
            .Add("Eintrag", GetType(Date))
            .Add("OrtderStöerung", GetType(String))
            .Add("Stördauer", GetType(Integer))
            .Add("ArtderStörung", GetType(String))
            .Add("MaschinenID", GetType(Integer))
        End With

   Private Function GetFreq1(ByVal week As Integer, _
       year As Integer, masch As Integer) As DataTable
 
        Dim cal As Globalization.Calendar = _
           Globalization.CultureInfo.CurrentCulture.Calendar
 
        Dim q = From row As DataRow In dt
              Let wk As Integer = _
                cal.GetWeekOfYear(row.Field(Of Date)("Eintrag"), _
                Globalization.CalendarWeekRule.FirstDay, DayOfWeek.Monday)
              Where year = row.Field(Of Date)("Eintrag").Year _
                AndAlso wk = week _
                AndAlso row.Field(Of Integer)("MaschinenID") = masch
              Group By art = row.Field(Of Integer)("ArtderStörung") Into Count()
 
        Dim df As New DataTable
        df.Columns.Add("ArtderStörung") : df.Columns.Add("Count")
 
        For Each el In q
            df.Rows.Add(el.art, el.Count)
        Next el
 
        Return df
    End Function