Trendlines and Forecast

[mikelee101]

Hello,
I have a set of data that I'm charting, which has the most recent data at
the top of the table. For example:

Month Units
Apr 350
Mar 275
Feb 325
Jan 365

In order to chart it so that the timeline goes from left to right, I'm using
the "Categories in Reverse Order" option.
I also have a linear trendline that I want to forecast out 3 periods.
However, since I've reversed the x-axis order, the forecast is going on the
wrong end of the data. I tried the Forecast Backward option, but it wouldn't
let me go above .5 of a period.
Does anyone know how to trick the trendline to forecast off the top of the
table as opposed to the bottom of the table?

Thanks for the help.

Mike

(xl2000, winxppro)

 

[John Mansfield]

Mike,

One option would be to totally omit the use of the built-in charting
trendline. As the alternative, use Excel's built-in functions to create the
trend line via worksheet cells. After the trend has been created in your
woksheet, chart it as another series just as you would your original data.

 

[Jon Peltier]

Mike -

If you use real dates: April 1, 2004 etc., Excel will plot in increasing
date order. You can extend it forward (beyond April) indefinitely.
Apr 350
Mar 275
Feb 325
Jan 365

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Peltier Technical Services
Tutorials and Custom Solutions
http://PeltierTech.com/
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