[Haskell-cafe] Phase correction?

[Mario Lang]

Henning Thielemann <lemming at henning-thielemann.de> writes:

> On Wed, 8 Jun 2022, Mario Lang wrote:
>
>> -- The naive question of an experimenting non-math coder person is:
>> -- Can a version of `at` be written which compensates for the phase
>> -- differences which runs in O(n) where n is the number of curve points?
>> -- Intuitively this should be possible given `d` (denominator).
>> at' :: Curve a -> Ratio b -> a
>> at' c t = undefined
>
> Information that is lost, is lost.

But is it really "lost", given that a Curve knows about all the
phase changes in the past?  I guess the simplest case would be
No interpolation.  Thats a single phase change.  My math is too bad, but
I guess given the denominator (sample rate) and the from and to value of
the change, the phase difference should be somehow computable?
If so, the next question would be if the linear interpolation case
could also be compensated for?
Ideally, every interpolation formula would have a phase compensation
function. If that is so, how computationally intensive would they be?

-- 
CYa,
  ⡍⠁⠗⠊⠕