Growth rate

Michael J Gebis (gebis@ecn.purdue.edu)
Thu, 24 Apr 1997 10:30:21 -0500 (EST)


> >A calculation I have worked out in a notebook but not coded up to get the
> >numbers for is computing (ave_time_uncoordinated/ave_time_coordinated)
> >not assuming a constant key rate, but instead a rapidly growing one.
> >We've had exponential growth with doubling time of 7-8 days for well
> >over a month now, I hope it lasts a good while longer.
>
> This is a feasible calc. but, from looking at the graphs I'd say that we
> may have linear growth instead of exponential growth. Though I could be
> incorrect...:)

Poplulation is typically modeled as a "sigmoid" curve, IE:
_____________
/
/
/
/
_____________/

(Use your imagination to make the corners smoother)

For the first half of the curve, the growth looks exponential. I fear
that we have passed this point, and are nearing the linear part of the
curve. For example, the "doubles every week" rule of thumb hasn't held for
the past few days.

I suspect that the growth could be modeled by a modified sigmoid with
a linear component, IE
___---
___---
/
/
/
_________________/

In other words, we've seen the exponential growth portion already, now
we will slowly (but steadily) grow.

It will be interesting to see how these predictions turn out.

-- 
Mike Gebis  gebis@ecn.purdue.edu  mgebis@eternal.net