This is taking me back to my days in university so if the info is not 100%
accurate then my appologies. Regression is excellent for interpolating
results but when you start to extrapolate and try to predict future values
the function starts to break down. Eventually the function will return values
that get either extremely large or extremely small (tends towards infinity).

For example if you plot weather forcasts it will quite accurately
interpolate missing values but if you use ti to make future predictions then
it breaks down more and more the further away you get form your know values.
--
HTH...

Jim Thomlinson


"OBR" wrote:

I performed a polynomial regression with dates and flow rates in Excel. The
result provides me wit a sixth degree equation in function of dates
(independent variable). For some reason, when I use the equation to predict
future flows the equation produces very large values. I am assuming it is due
to the numerical format of the dates in the cells. Does any one know how to
solve this issue?