'Re: [postgis-users] Nearest linestring given a point, a tolerance and a set of linestrings?'

[prev in list] [next in list] [prev in thread] [next in thread] 

List:       postgis-users
Subject:    Re: [postgis-users] Nearest linestring given a point, a tolerance and a set of linestrings?
From:       Nicklas_Avén <nicklas.aven () jordogskog ! no>
Date:       2013-01-23 14:14:58
Message-ID: 201301231414.r0NEEwtE011974 () mail2 ! space2u ! com
[Download RAW message or body]

[Attachment #2 (multipart/alternative)]

>> Second and very important
>> Using KNN distance as you do will not always give you the right answer since
>> the &lt;-> operator only works on the center of the bounding box, not the
>> geoemetry itself. So another geometry with the bbox-center much more far
>> away can come much closer than the one you have found. In this case it
>> happened to be the same and give correct result.
>
>Yes, but I think one could use &lt;#> instead of &lt;-> (if newest release
>is available):

No, &lt;#> calculates against the whole bounding box, still not the real geometry. 

/Nicklas
[Attachment #5 (unknown)]

<html>
<head>
</head>
<body><br />
=09
	<nicklas.aven@jordogskog.no>
>> Second and very important<br />
	=09
>> Using KNN distance as you do will not always give you the right answer s=
ince<br />
	=09
>> the &lt;-> operator only works on the center of the bounding box, not th=
e<br />
	=09
>> geoemetry itself. So another geometry with the bbox-center much more far=
<br />
	=09
>> away can come much closer than the one you have found. In this case it<b=
r />
	=09
>> happened to be the same and give correct result.<br />
	=09
><br />
	=09
>Yes, but I think one could use &lt;#> instead of &lt;-> (if newest release=
<br />
	=09
>is available):<br />
		<br />
		</nicklas.aven@jordogskog.no>
	<div>
		<nicklas.aven@jordogskog.no>No, &lt;#> calculates against the whole bound=
ing box, still not the real geometry.&nbsp;</nicklas.aven@jordogskog.no></d=
iv>
	<div>
		<nicklas.aven@jordogskog.no><br />
			</nicklas.aven@jordogskog.no></div>
	<div>
		<nicklas.aven@jordogskog.no>/Nicklas</nicklas.aven@jordogskog.no></div>
</body>
</html>

_______________________________________________
postgis-users mailing list
postgis-users@lists.osgeo.org
http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users

[prev in list] [next in list] [prev in thread] [next in thread] 