Trend line phase changes

[Lee C.]

Hi. I am trying to figure out how to implement phase changes in an
Excel chart trend line. This is possible on the charting here:
http://www.interventioncentral.org/htmdocs/tools/chartdog/chartdog.shtml

To explain, this would allow me to indicate a place on the x axis
where I've started doing something differently that may affect the
trend and I want the trend line to be recalculated from that point on
the x axis where the change is implented.

From the ChartDog Web site:
"Marking Phase Changes . In ChartDog, you can mark significant 'phase
changes' on the graph by clicking the 'Phase Change?' box. (See Figure
5E for an example.) Phase changes are locations in a data series in
which a modification has taken place in the program or treatment being
measured you predict should significantly alter the trend of the
data--e.g., a major alteration of a student's academic program. When
you select a phase change for a specific observation date, ChartDog
inserts a break into the charted line-plot(s) and places a vertical
dividing line on the graph to mark the phase change. (Refer to Figure
6B for an example of a charted phase change)."

I've found this:
http://www.geocities.com/jonpeltier/Excel/Charts/ComboCharts.html#AddLine
But, it doesn't seem to help either.

Thanks in advance for any help or suggestions.

, Lee

 

[Tushar Mehta]

Plot the data before and after the 'phase change event' as separate
series. Now, create a trendline for each series. By overlapping the
last point of the first series with the first point of the next series
and with appropriate formatting you can make the two series look like
one.

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions