[time-nuts] exponential+linear fit

[Jim Lux]

On 10/4/13 2:54 PM, Alan Melia wrote:
> Jim it may not be helpful but had you thoughtof expanding the
> exponential as the first few terms of an infinite series to see if it
> simplifies fitting?

Hmm..

So the tradeoff is "fit polynomial with higher order" (because the 
polynomial basically is the first few terms of a Taylor expansion for 
exp(x)).  My DC and linear term in X basically add to the terms for the 
exponential.
vs
linearize the data by taking the log of each point, then fit a straight 
line.

Without grinding through a benchmark, I have to believe that calculating 
the various powers of the inputs to do a least squares has to be 
computationally lighter load than doing log, and then exp


I'll try attaching a plot of some sample data.


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