BUG: MSChart Control Can't Plot Data Points >15 Decimal Places

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, version 5.0

SYMPTOMS

When the Chart Control is assigned an array of data points containing 16 or more decimal places, those data points do not appear when the chart is updated.

RESOLUTION

There are two ways to deal with this issue:

1. Formatting the number to 15 or fewer decimal places.

2. Using the SetData property on each data point.

Workaround 1

Before setting the chart to the variant array, "truncate" the decimal values to 15 places or less as seen in the form_load event below:

   Private Sub Form_Load()
      Dim data_pts(1 To 3, 1 To 2) As Variant
      dim i as integer

      data_pts(1, 1) = "R1"
      data_pts(1, 2) = 5.48487730596136E-02
      data_pts(2, 1) = "R2"
      data_pts(2, 2) = 7.04216678154124E-02
      data_pts(3, 1) = "R3"
      data_pts(3, 2) = 3.10863837084563E-04

      For i = 1 To 3
         data_pts(i, 2) = CDbl(Format(data_pts(i, 2), "0.000000000000000"))
         'Truncate data_pts to 15 decimal places of precision
      Next

      MSChart1 = data_pts

   End Sub

Workaround 2

Use the SetData method to add the data to the chart instead of setting the chart to the variant array. To use this workaround, rewrite the Form_Load event to look like this instead:

   Private Sub Form_Load()

      With MSChart1

         .RowCount = 3
         .ColumnCount = 1

         .DataGrid.SetData 1, 1, 5.48487730596136E-02, False
         .DataGrid.SetData 2, 1, 7.04216678154124E-02, False
         .DataGrid.SetData 3, 1, 3.10863837084563E-04, False

      End With

   End Sub

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products noted at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

To reproduce the problem, follow the steps below:

1. Start a new project. Form1 is created by default.

2. Choose Project -> Components from the Visual Basic menu, and then check the Microsoft Chart Control.

3. Add an MSChart control to Form1.

4. Add the following code to the Load event of Form1:

         Dim x(1 To 3, 1 To 2) As Variant
   

         x(1, 1) = "Value1"
         x(1, 2) = 5.48487730596136E-02
         x(2, 1) = "Value2"
         x(2, 2) = 7.04216678154124E-02
         x(3, 1) = "Value3"
         x(3, 2) = 3.10863837084563E-04
   

         MSChart1 = x
   

5. Run the project and note that the data does not appear on the chart.