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Re: How long is a piece of string?
Posted by: Andrew Dodson
Date: August 18, 2009 01:48PM

If it is degrees, then shouldn't this formula output 90?

--------
SET @pt1 = ASBINARY(GeomFromText('POINT(0 0)')), /** equator, meridian line */
@pt2 = ASBINARY(GeomFromText('POINT(90 90)')); /** north pole */

SELECT GLength(LineStringFromWKB(LineString(@pt1,@pt2))) AS distance;
--------
output
127.279

... which is equal to trig function SQRT(90^2 + 90^2), thats all this function is doing.



as expected this works
--------
SET @pt1 = ASBINARY(GeomFromText('POINT(0 0)')), /** equator, meridian line */
@pt2 = ASBINARY(GeomFromText('POINT(90 0)')); /** north pole */

SELECT GLength(LineStringFromWKB(LineString(@pt1,@pt2))) AS distance;
--------
output
90


How intolerable!

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