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<body>If I understand you right your assumption is true.
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<div>What makes you wondering?</div>
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<div>In 2d you will always get the distance to a vertexpoint in at least one of the two geometries.</div>
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<div>You can use ST_ShortestLine to see between what points the distance is calculated.</div>
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<div>So:</div>
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<div>SELECT ST_Distance('LINESTRING(1 1, 1 10)'::geometry, 'LINESTRING(2 5, 10 5)'::geometry);</div>
<div> returns 1</div>
<div>and </div>
<div>SELECT ST_AsText(ST_ShortestLine('LINESTRING(1 1, 1 10)'::geometry, 'LINESTRING(2 5, 10 5)'::geometry));</div>
<div>returns 'LINESTRING(1 5, 2 5)'::geometry</div>
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<div>geography type calculations is of course another story.</div>
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<div>HTH</div>
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<div>Nicklas</div>
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2013-10-18 Peter Hopfgartner wrote:<br />
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I took it for granted, that ST_Distance between two two dimensional <br />
>geometries followes the definition of<br />
><br />
>dist(A, B) = inf(d(a,b)), where a is an arbitrary point in set A and b <br />
>an arbitrary point in set B and d() is the euclidean distance<br />
><br />
>For some reason I'm now wondering if my assumption is true.<br />
><br />
>Thanks for your patience,<br />
><br />
>Peter<br />
><br />
>-- <br />
>Peter Hopfgartner<br />
>R3 GIS<br />
><br />
>web : http://www.r3-gis.com<br />
><br />
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