Re: what tool for extrapolation beyond input range?

[Paul E Condon <pecondon@mesanetworks.net>]

On Sat, Feb 05, 2005 at 10:39:26AM +0800, Dan Jacobson wrote:
> What Debian tool can I use to answer
>    If I sold
>    4 burgers at 4:00
>    5 burgers at 5:00
>    6 burgers at 6:00
>    how many burgers might I be expected to sell at 7:00?
> plotutils: no. gmt: no. gnuplot: no(?)  All of them dare not to
> extrapolate beyond the input edges.
> 

In gnuplot:

gnuplot> y(x)= ((6-4)/(6-4))*(x-4)+4
gnuplot> plot [4:8] y(x)
  
will give you what you're asking for. This "solution" ignores
the data at 5:00. To use that data, one needs a quadratic
expression which is too complicated for me to generate on the
fly while typing. But beware. You have asked a foolish question.

I would not recommend gnuplot for real data fitting, but for
bad questions any blunt tool will do.

-- 
Paul E Condon           
pecondon@mesanetworks.net