[Lazarus] ComparePoints func

[Reimar Grabowski]

On Wed, 26 Jul 2017 18:53:34 +0100
Graeme Geldenhuys via Lazarus <lazarus at lists.lazarus-ide.org> wrote:

> On 2017-07-26 17:27, Alexey via Lazarus wrote:
> > Hm, in my app Int makes sense: i need to compare Points in binary
> > search, and see: >, <, =.  
> 
> Ever heard of Manhatten Length? That would be a more logical approach. 
If a metric would be more logical (I don't know why exactly it should be but whatever) the euclidean metric would be even more logical, wouldn't it?

> It is a commonly used length calculation for points.
That sounds horrible.
Is length really used like this?
The length of two points???
Metrics are distance functions.
 
>    http://en.wikipedia.org/wiki/Taxicab_geometry
Any 2 dimensional metric can be used.
But it may totally not be the thing the TC needs as the metric conditions may not be desirable in his context.

The point is (and Michael made it already) that there is no definition of how to compare points. You have quite a lot of options and the current problem determines which function to use.
Therefore it makes no sense to introduce a general ComparePoints-function.

R.