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<div class="post-text" itemprop="description"> Hello postgis'ers,<br>
<br>
somehow I can't understand the results of ST_Project, but maybe
this problem is just me being stupid (again):<br>
I just want to project a point in North, East, South and West
direction.<br>
<br>
Note:<br>
I use geography-type here, but the results are the same for
geometry.<br>
I use a rather long distance, because I need it, at least in one
direction, for my application. Because of this I found the
"problem" in the first place.<br>
<br>
With the direction north, everything is as I expect it:<br>
<br>
<code>SELECT ST_AsText(ST_Project('POINT(-30 -0.5)'::geography,
1e7, radians(0))); <br>
st_astext -----------------------------
<br>
POINT(-30 89.4874128664049)
</code><br>
<br>
But in the other directions, here for example East, I get this:<br>
<br>
<code>SELECT ST_AsText(ST_Project('POINT(-30 -0.5)'::geography,
1e7, radians(90))); <br>
st_astext ---------------------------------------------
<br>
POINT(59.8315233716443 0.00116689648502556)
</code><br>
<br>
Shouldn't this be <code>POINT(59.8315233716443 -0.5)</code> ? Why
are both coordinates changing?<br>
<br>
This behaviour occurs in all directions save north. <br>
<br>
I'm new to the whole earth coordinate system-stuff so maybe I
missed something, but I thought that when one walks directly west
(or south) one would, by definition, not leave the current
longitude (or latitude)-line but only change the other.<br>
<br>
Any help would be appreciated!
<br>
Thank you.<br>
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