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Re: GIS functions in MySql 5.1.35 are not 3D
Posted by: Mike McCutcheon
Date: July 20, 2010 05:06PM

Here's a link to compare a proper 3D circle (not created with a MySQL GIS function) with a buffer created by using the MySQL 5.1.35 buffer() function:

http://www.around-the-world.co.uk/public/circle.php

It's just a demo so it doesn't have any validation, so please just use valid decimal latitude (+90 to -90) and longitude (-180 to + 180). Also don't define a circle which will cross the antimeridian.

On the equator, the buffer is the same as the circle. As you move towards a pole, the circle remains a circle but the buffer gets distorted because the function doesn't seem to take into accounts that the lines of longitude get closer at the poles.

As I have said before, I apologize if I am wrong, but I hope someone else will comment one way or another ASAP because we don't want wrong GIS MySQL functions and we don't want inaccurate comments.

Meanwhile, I'm going to post a bug report.

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Re: GIS functions in MySql 5.1.35 are not 3D
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