Can't add logarithmic trendline PowerPoint 2007

[Elizabeth Swoope]

I have an X-Y graph showing the length of sheepshead (fish) at ages from
hatching to 20 years. I can add trendlines in exponential, linear,
polynomial, and moving average. However, the data are logarithmic but when I
choose either logarithmic (or power, just to test), there's no line. The
Format Trendline box disappears for those two options.

The original graph, which I did in ancient Freelance, works beautifully with
a logarithmic line. Why can't I get one in PowerPoint?

Thanks,

liz

 

[Echo S]

All I can say is that a quick test shows a log trendline working fine here
in PPT 2007.

Since PPT 2007 uses Excel for its charting, you might ask this in the Excel
charting group. Or, if you're patient, I bet one of the Excel MVPs will be
by to participate in this thread, as they often weigh in on the charting
questions we see here.

 

[Andy Pope]

Hi,

I would say you have a zero or negative value in your data series.
Try changing the zero to 0.00001 and the Log line will appear or you can
now add and format it.

Cheers
Andy