Hi,

> If you try to "normalize" WGS84=lat+lon -coordinates to be positive
> (Math.abs)

Using Math.abs is the wrong solution of course: it folds negative
number to positive number.

What I mean with "normalize" is, scale value so that it is between the
minimum and maximum. To scale a value x (where -10 <= x <= 10) to (0
<= x2 <= 1000), use the formula:

min = -10;
max = 10;
factor = 1000;
x2 = (x - min) / (max - min) * factor;

I have added a few helper methods to the MultiDimension tool:
http://code.google.com/p/h2database/source/browse/trunk/h2/src/main/org/h2/tools/MultiDimension.java

Regards,
Thomas


, you run into
> a heap of special cases trying to formulate your bounding-area correctly
> along the 0 latitude and 0 longitude -lines.
> (geocoordinates are the one most importent use-case for multidimensional
>  indexing.)
>
>>> Faced with that we can get our code to work with a minor change to these
>>> methods, allowing negative coordinates too.
>>
>> I didn't fully read the code yet, but I guess you also normalized the values?
>
> It´s not my code. I´m just the maintainer and asked for the permission to use
> a patch submitted by a developer to fix a bug.
>
>>
>>> However since H2 is Apache
>>> and our code is GPL, I´d lilke to ask who wrote this particular code and if
>>> he/she is fine with including a patched version of
>>> addMortonRanges() getMortonRanges() and getMultiDimensionResult()
>>> in our code.
>>
>> I wrote this code, and you can use it.
>>
>> I guess you need to write somewhere that the code originates from H2,
>> and that you have permission to use it. So that others don't think
>> that I copied the code from your project to the H2 project...
>
> Thanks.
> No problem there.
>
> Marcus
>
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