Trend line trouble.......

[Rob Murphy]

Hi there. I have a chronological dataset of approximately 30+ points on
excel, graphed up. I would like to add a linear trend line to this dataset,
but only based on the last 10 points (rolling as I add new data). Basically,
I want to retain 30+ weeks of data on the graph, but only want to see the
trend of the last 10 weeks.....

Tricky one?

Many thanks

Rob

 

[Jim Cone]

Rob,
It has been a while since I last did this...
Add a second (duplicate) series, make it invisible, add the trend line to the new series.
If I remember correctly all of the point values should be zero except for the
last ten points. Tell the chart to not plot zeros.
--
Jim Cone
San Francisco, USA
http://www.realezsites.com/bus/primitivesoftware


"Rob Murphy" <Rob (e-mail address removed)>
wrote in message
Hi there. I have a chronological dataset of approximately 30+ points on
excel, graphed up. I would like to add a linear trend line to this dataset,
but only based on the last 10 points (rolling as I add new data). Basically,
I want to retain 30+ weeks of data on the graph, but only want to see the
trend of the last 10 weeks.....
Tricky one?
Many thanks
Rob

 

[Rob Murphy]

Hi Jim

You're right, it can be done this way. To be honest I was being a bit lazy
and hoping there was someway I could 'modify' the trend line to always
automatically pick up the last 10 points. The reason I'm being a bit lazy is
tis is part of my companies whole KPI reporting and there are about 90 graphs
(a bit crazy I know!!!).

If there isn't a 'funky' way of modifying the trendline itself, I'll crack
on with this solution.

Thanks for your help

Rob

 

[Jon Peltier]

No lazy way out of this one, I'm afraid.

- Jon

 

[Rob Murphy]

OK, thanks very much...........perhaps in the next version of Excel......

Regards

Rob