MySQL Forums
Forum List  »  GIS

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.

Options: ReplyQuote


Subject
Views
Written By
Posted
Re: GIS functions in MySql 5.1.35 are not 3D
2777
July 20, 2010 05:06PM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.