Calculating instantaneous phase of a simple signal

I would define "best" as the the limit of this calculation as the sample
rate approaches infinity:

rise/run between each adjacent data point of instantaneous phase

I could simply bump my sample rate up very high, but there would be
advantages to having a function instead of having to numerically calculate
the rise/run between each adjacent data point.  Having a formula would make
implementing this calculation in certain environments other than Scilab or
Matlab possible/practical, such as in VST or Reaktor.


Thanks again for setting me straight earlier Dale.  Were it not for that,
I may have gone on thinking that the rate of change of phase was constant,
and not calculated its rise/run.  When I saw that plot of approximate
instantaneous frequency I really jumped with joy, it was exactly the type
of thing I was hoping to find.

>You have a calculation for F:
>http://www.studioprofessor.com/images/instantaneousfrequencyestimatio...
>so just do it as accurately as you like by reducing the size of the
>interval used and it's done.
>
>If that isn't 'best' then you need to explain what the criteria for
>'best' would be.
>
>Dale B. Dalrymple
>
>