Hi list, I think that I have just discovered an inconsistency in the PostGIS manual. Today, I have tried to use the function ST_Locate_Between_Measures that takes a geometry and two floating point numbers (see [1] in the manual). The manual says, that this function "supports M coordinates". So, in my eyes, I should be able to call this function with geometries that don't have any M coordinates as well. Two examples:
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1) Function call without M coordinate:
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SELECT ST_Locate_Between_Measures(ST_GeomFromEWKT('LINESTRING(33296361.4755929
5980762.99091387,33296357.0886 5980746.8462,33296350.5402
5980729.1851,33296336.2529 5980715.4926,33296331.0934
5980705.9678,33296328.3154 5980697.4349)'), 1.5, 3);
the result:
ERROR: Geometry argument does not have an 'M' ordinate
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2) Function call with M coordinate:
-----------------------------------
SELECT ST_Locate_Between_Measures(ST_GeomFromEWKT('LINESTRINGM(33296361.4755929
5980762.99091387 0,33296357.0886 5980746.8462 4,33296350.5402 5980729.1851
8,33296336.2529 5980715.4926 13,33296331.0934 5980705.9678 20,33296328.3154
5980697.4349 39)'), 1.5, 3);
the result:
010200004002000000809B497DFEC07F41C502F23B95D05641000000000000F83FB32FF762FEC07F4189E378B893D056410000000000000840
As you can see in the upper two examples, I was not able to call the
ST_Locate_Between_Measures function with geometries that don't have
any M coordinates - it seems that M coordinates are REQUIRED but not
SUPPORTED. It this right? And should the manual beeing fixed? Or is
there a mistake in the function call in the first example?
Regards,
Ingo
[1]
http://postgis.refractions.net/documentation/manual-1.5/ST_Locate_Between_Measures.html
--
Ingo Weinzierl <[email protected]> | Tel.: +49 (0)541-33 508 3773
Intevation GmbH, Neuer Graben 17, 49074 OS | AG Osnabr�ck - HR B 18998
Gesch�ftsf�hrer: Frank Koormann, Bernhard Reiter, Dr. Jan-Oliver Wagner
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