Charlie sent me his workbook, and after fiddling around for a bit, I
discovered the problem. As suspected, it was something stupid. Not
something Charlie has done, just a funny way Excel works.
When you make a line chart, Excel assigns category (X axis) labels to
the first series, then leaves these categories out of the other series.
The first series have the labels explicitly defined, as in this series
formula:
=SERIES(Totals!$C$4,Totals!$A$5:$A$49,Totals!$C$5:$C$49,1)
Subsequent series do not have it defined, shown by the missing argument
here:
=SERIES(Totals!$D$4,,Totals!$D$5:$D$49,3)
Excel by default uses the primary X values for the secondary series,
until a secondary X axis is added. When I copied the X Values range,
Totals!$A$5:$A$49, from the first formula, and pasted it into the second:
=SERIES(Totals!$D$4,Totals!$A$5:$A$49,Totals!$D$5:$D$49,3)
the missing trendlines magically appeared. The Source Data dialog showed
this X Values range, but these are the primary X values, and the
secondary X values ox was blank. Even though Excel uses the same X
values to plot the secondary series, they were ignored when determining
the trendline.
- Jon
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Jon Peltier, Microsoft Excel MVP
Peltier Technical Services
Tutorials and Custom Solutions
http://PeltierTech.com/
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