使用 Excel VBA 修改标记透明度

Question

Lets say I have the table below and I want to make a scatter plot of it.

X    Y      Weight

1    0.5    12
2    0.1    23
3    0.2    36
4    0.5    27
1    0.2    4

I am looking for a way to set the transparency of marker based on values in a column so that each point's marker has its individual transparency level which might not be the same as the other points. The reason I want this is that the weight of the points is not equal.

One solution would be to create further number of points (Weight - 1) manually and plot them all with an appropriate transparency level. Another solution would be to set the marker transparency level for each point manually. However, none of these are logical as the number of the points is really large!

I have tried the below with VBA but no luck with it.

Sub TransparencyModifier()
'
' TransparencyModifier Macro
'

'

Dim i as Integer
For i = 1 to 5
    ActiveChart.SeriesCollection(1).Select
    ActiveChart.SeriesCollection(1).Points(i).Select
    With Selection.Format.Fill
        .Transparency = Cells(i+1,3).Value/100
    End With
Next i
End Sub

Any help is appreciated

Answer 1

There is a bug in Excel (I'm using Excel 2013). When you set the Fill transparency, the line style goes to auto, and you don't see the transparency. If you via VBA set the style back to solid, transparency gets set to 0.

I was able to use the following workaround:

1. MANUALLY Set your chart's Fill color to white (or same as your chart background). If you set it in code, it will REVERT...

2. Add before the With line

   a. Selection.MarkerSize = 2 and
   b.Selection.Border.LineStyle = msoLineFileNone

and

3. Change your With line to With Selection.format.Line

4. Add before the .transparency =

   a. .Visible = msoTrue and
   b..ForColor.ObjectThemeColor = msoThemeColorAccent1

Resulting code block:

Sub TransparencyModifier()
Dim i As Integer
For i = 1 To 5
    ActiveChart.SeriesCollection(1).Select
    ActiveChart.SeriesCollection(1).Points(i).Select
    Selection.MarkerSize = 2
    Selection.Border.LineStyle = msoLineFillNone
    With Selection.format.Fill
        .Visible = msoFalse
    End With
    With Selection.format.Line
        .Visible = msoTrue
        .ForeColor.ObjectThemeColor = msoThemeColorAccent1
        .transparency = Cells(i + 1, 3).Value / 100
    End With
    Selection.Border.LineStyle = msoLineFillNone
Next i
End Sub

Answer 2

I made another solution to this writing a small python script which creates more points based on the weight of each point eg if the weight of a point is 12 then 12 identical points with the specifications of this point are created. Then saved all these in a csv and plotted it and changed opacity for all markers manually (this is easy) to a number that gave me satisfying result. As the extra points created overlay each other, the final product will show the weight of each point as well.

Answer 3

Old post but if people have the same problem this worked for me, found it after some googling.

Dim chtTemp As Chart
Dim serTemp As Series

Set chtTemp = ActiveSheet.ChartObjects(1).Chart ' your chart
Set serTemp = chtTemp.SeriesCollection(1) ' the series that you want to make transparent

With serTemp.Format.Fill
    .Solid
    .Visible = True
    .BackColor.RGB = RGB(255, 0, 0)
    .ForeColor.RGB = RGB(255, 0, 0)
    .Transparency = 0.3
End With