Is "Deamortizing AA's and Dynamic Arrays" of any interest?

-manfred

Manfred Nowak Wrote:

> Is "Deamortizing AA's and Dynamic Arrays" of any interest?
> 
> -manfred

By "Deamortizing" you mean "reduce the cost of" right?
I'm not an accountant.

- Dan

Dan wrote:
> Manfred Nowak Wrote:
>> Is "Deamortizing AA's and Dynamic Arrays" of any interest?
> By "Deamortizing" you mean "reduce the cost of" right?
> I'm not an accountant.

I think he means trading occasional "longer" waits for regular
short waits....

Regards, Frank

On Mon, 23 Apr 2007 19:32:12 +0000 (UTC), Manfred Nowak wrote:

> Is "Deamortizing AA's and Dynamic Arrays" of any interest?

I can't really say because I'm not sure what you mean by "deamortizing".

If "amortizing" means spreading the cost over a longer period of time (many small payments over the time), then the reverse would mean that you intend to 'spend' the cost in bigger hits (a few large payments over the time)

So I expect you mean something like implementing AA and DynArr by doing a lots of 'pre-processing' work at create or expand time rather than little bits of work for each new element.

If, then yes I'd be interested.

-- 
Derek
(skype: derek.j.parnell)
Melbourne, Australia
"Justice for David Hicks!"
24/04/2007 10:32:11 AM

Derek Parnell wrote

> I can't really say because I'm not sure what you mean by "deamortizing".


Amortizing is explained here: http://en.wikipedia.org/wiki/Amortized_analysis

So: 0ffh had the right interpretation of the word "deamortizing". This technical term came to my knowledge quite recently.

-manfred

On Mon, 23 Apr 2007 22:14:46 +0200, 0ffh wrote:

> Dan wrote:
>> Manfred Nowak Wrote:
>>> Is "Deamortizing AA's and Dynamic Arrays" of any interest?
>> By "Deamortizing" you mean "reduce the cost of" right?
>> I'm not an accountant.
> 
> I think he means trading occasional "longer" waits for regular short waits....

In that case, Manfred probably used the term "Amortizing" rather than "De-Amortizing". To me, the 'de-' prefix implies an operation that reverses the effect of amortizing the behaviour. In other words, 'de-amortizing' means bunching up the costs into larger lumps and 'amortizing' means spreading the costs into smaller lumps. In both case, the lumps would be predictable rather than probabilistically determined.

Manfred has quoted a Wikipedia reference and it seems to uphold my understanding of the term, but I suppose I could just be reading it incorrectly.

-- 
Derek
(skype: derek.j.parnell)
Melbourne, Australia
"Justice for David Hicks!"
24/04/2007 12:38:13 PM

Derek Parnell wrote:
> On Mon, 23 Apr 2007 22:14:46 +0200, 0ffh wrote:
> In that case, Manfred probably used the term "Amortizing" rather than
> "De-Amortizing". To me, the 'de-' prefix implies an operation that reverses
> the effect of amortizing the behaviour. In other words, 'de-amortizing'
> means bunching up the costs into larger lumps and 'amortizing' means
> spreading the costs into smaller lumps. In both case, the lumps would be
> predictable rather than probabilistically determined.

I'm not 100% sure here how the language should be used.
My interpretation runs thus:

"Amortising" is just a mathematical "trick" to make different sorts of
algorithms comparable in terms of computational cost per function call,
by spreading lumped costs equally over all calls.
Therefore, I interpret "deamortising" a piece of /concrete code/ as
removing the need for this "spreading trick" by replacing a "lumpy"
method with a more "incremental" one.

Regards, Frank