Microsoft.Office.Interop.PowerPoint Chart - with broken y-Axis - winforms

Question

We are using the Interop PowerPoint Chart type to generate an area chart as shown in the figure. We need the "broken" y-Axis. We dont want the break on the bars itself - we need the break only on the y-Axis. But are unable to find a property or a method to achieve this.
This a winforms application. Would really appreciate some pointers...

Answer 1

Accidentally stumbled upon this question, and I let my curiosity takes over.
I got how it's done taken from this site.
I'm using example data from above site for this walkthrough.
The step roughly like this:
Assign cut value for data separation. Separate data using a cut value (I use cut value 7,500,000 for the example)
This is data separation from the example (above is the original, below is the separated):
May June July
London 1,234,565 1,452,369 1,478,852
Paris 2,363,645 34,568,876 5,562,413
Madrid 32,645,254 3,211,654 5,857,421
Brussels 5,914,753 5,544,221 3,620,015
Lisbon 5,824,676 4,541,258 4,015,876
Munich 2,501,478 6,325,698 4,569,872
May June July Column4 Column5 Column6
London 1,234,565 1,452,369 1,478,852 0 0 0
Paris 2,363,645 7,500,000 5,562,413 0 34,568,876 0
Madrid 7,500,000 3,211,654 5,857,421 32,645,254 0 0
Brussels 5,914,753 5,544,221 3,620,015 0 0 0
Lisbon 5,824,676 4,541,258 4,015,876 0 0 0
Munich 2,501,478 6,325,698 4,569,872 0 0 0
Assign Column4, Column5, and Column6 into secondary axis.
Dim c As Microsoft.Office.Interop.PowerPoint.Chart
Dim sc As Microsoft.Office.Interop.PowerPoint.SeriesCollection = Nothing
Dim sr As Microsoft.Office.Interop.PowerPoint.Series = Nothing
sc = c.SeriesCollection
For i = 4 To sc.Count
sr = sc.SeriesCollection(i)
sr.AxisGroup = Microsoft.Office.Interop.PowerPoint.XlAxisGroup.xlSecondary
Next
Change Primary and Secondary Axis scale to fit as though the chart was separated. I change the primary axis scale from 0 to 1.6e7, and secondary axis scale from -7.0e7 to 7.0e7. At the same time, change display unit in millions, and remove all gridlines.
Dim ax As Microsoft.Office.Interop.PowerPoint.Axes
Dim axpri As Microsoft.Office.Interop.PowerPoint.Axis
Dim axsec As Microsoft.Office.Interop.PowerPoint.Axis
ax = c.Axes
axpri = ax.Item(Microsoft.Office.Interop.PowerPoint.XlAxisType.xlValue, _
Microsoft.Office.Interop.PowerPoint.XlAxisGroup.xlPrimary)
axsec = ax.Item(Microsoft.Office.Interop.PowerPoint.XlAxisType.xlValue, _
Microsoft.Office.Interop.PowerPoint.XlAxisGroup.xlSecondary)
axpri.MinimumScale = 0
axpri.MaximumScale = 1.6e7
axpri.DisplayUnit = Microsoft.Office.Interop.PowerPoint.XlDisplayUnit.xlMillions
axpri.HasMajorGridlines = False
axpri.HasMinorGridlines = False
axsec.MinimumScale = -7.0e7
axsec.MaximumScale = 7.0e7
axsec.DisplayUnit = Microsoft.Office.Interop.PowerPoint.XlDisplayUnit.xlMillions
axsec.HasMajorGridlines = False
axsec.HasMinorGridlines = False
Change Primary and Secondary Axis number format so that each axis only show its own intended value. Primary Axis more than 8M will not be shown, and Secondary Axis less than 30M will not be shown.
axpri.TickLabels.NumberFormat = "[<=8]0;;;"
axsec.TickLabels.NumberFormat = "[>=30]0;;;"
Recolor series in Secondary Axis to match series in Primary Axis.
Dim srPrev As Microsoft.Office.Interop.PowerPoint.Series = Nothing
For i = 4 To sc.Count
sr = sc.SeriesCollection(i)
srPrev = sc.SeriesCollection(i - 3)
sr.Format.Fill.ForeColor.RGB = srPrev.Format.Fill.ForeColor.RGB
Next
Delete Legend for Column4, Column5, and Column6 for a seamless Chart Legend.
c.Legend.LegendEntries(4).Delete()
c.Legend.LegendEntries(5).Delete()
c.Legend.LegendEntries(6).Delete()
[Optional] Add a neat color gradient for Data Points that exceed cut values.
Dim p As Microsoft.Office.Interop.PowerPoint.Point = Nothing
p = c.SeriesCollection("June").Points("Paris")
p.Format.Fill.TwoColorGradient(Microsoft.Office.Core.MsoGradientStyle.msoGradientHorizontal, 1)
p.Format.Fill.GradientAngle = 270
p.Format.Fill.GradientStops.Insert(p.Format.Fill.ForeColor.RGB, 0.8)
p.Format.Fill.GradientStops.Insert(p.Format.Fill.BackColor.RGB, 0.97)
p = c.SeriesCollection("May").Points("Madrid")
p.Format.Fill.TwoColorGradient(Microsoft.Office.Core.MsoGradientStyle.msoGradientHorizontal, 1)
p.Format.Fill.GradientAngle = 270
p.Format.Fill.GradientStops.Insert(p.Format.Fill.ForeColor.RGB, 0.8)
p.Format.Fill.GradientStops.Insert(p.Format.Fill.BackColor.RGB, 0.97)
p = c.SeriesCollection("Column5").Points("Paris")
p.Format.Fill.TwoColorGradient(Microsoft.Office.Core.MsoGradientStyle.msoGradientHorizontal, 1)
p.Format.Fill.GradientAngle = 90
p.Format.Fill.GradientStops.Insert(p.Format.Fill.ForeColor.RGB, 0.7)
p.Format.Fill.GradientStops.Insert(p.Format.Fill.BackColor.RGB, 0.95)
p = c.SeriesCollection("Column4").Points("Madrid")
p.Format.Fill.TwoColorGradient(Microsoft.Office.Core.MsoGradientStyle.msoGradientHorizontal, 1)
p.Format.Fill.GradientAngle = 90
p.Format.Fill.GradientStops.Insert(p.Format.Fill.ForeColor.RGB, 0.7)
p.Format.Fill.GradientStops.Insert(p.Format.Fill.BackColor.RGB, 0.95)
Voila! Hard work pays off, a broken y axis in PowerPoint chart.