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<div align="left">yes, there was a lot of good information. Also the topological part was very informative. The rest I haven't read yet</div>
<div align="left">Great</div>
<div align="left"> </div>
<div align="left">/Nicklas<br />
<br />
2010-01-23 Paul Ramsey wrote:<br />
<br />
LRS needs to be done carefully, so as to not make it (a) more muddled<br />
>than it already is or (b) less useful. Right now we have two sets of<br />
>functions, some that work on measured geometries, and some that work<br />
>on unmeasured. And, as you note, we generally ignore the third<br />
>dimension in calculating the proportionality of things. There's some<br />
>ideas on the unification here:<br />
><br />
>http://opengeo.org/products/coredevelopment/postgis/lrs/<br />
><br />
>I think the simplest approach to the third dimension is to say "if<br />
>it's there, it's relevant" and include it in calculations of<br />
>proportional length. (That said, I just now ignored it in my<br />
>implementation, I'm such a flatlander.)<br />
><br />
>Paul<br />
><br />
>On Fri, Jan 22, 2010 at 4:45 PM, Nicklas Avén<br />
>
<nicklas.aven@jordogskog.no></nicklas.aven@jordogskog.no> wrote:<br />
>> Hallo<br />
>><br />
>> I have thought that I should raise some ideas about the line reference<br />
>> functions after this release. I mention it noe because it is a close<br />
>> subject.<br />
>><br />
>> I would like to rewrite the linereferencing functions like ST_Line_Substring<br />
>> to do the measure in all 3 dimensions. I am not sure I suggest that there<br />
>> should be a different behaviour in that function but rather make a new that<br />
>> also handles the measure in units like meters instead of parts of the whole<br />
>> line.<br />
>><br />
>><br />
>><br />
>> But the thing that was connected to this question was this about measuring<br />
>> in 2 or three dimensions. Does this customer wants it in 2D measuring or<br />
>> will he or she only work in 2 D so it doesn't matter.<br />
>><br />
>> What I mean is that if we want to go against 3Dmeasuring at line referencing<br />
>> maybe that should be included in the bbeginning on this one?<br />
>><br />
>> Just a thought.<br />
>><br />
>> What is needed as I understands it is just another function like<br />
>> distance3d_pt_pt that uses 3 dimensions in pythagora theorem.<br />
>><br />
>> In this function it would not matter that is only following the ground or a<br />
>> line that has the same angel to the ground all the way. But it would be a<br />
>> difference on a line following the ground and then suddenly continuing ut on<br />
>> a mountain or something like that.<br />
>> Just a thought<br />
>><br />
>> /Nicklas<br />
>> 2010-01-22 Paul Ramsey wrote:<br />
>><br />
>> All,<br />
>>><br />
>>>I have a client who needs a custom function added. Since we're well into<br />
>>> release, obviously the SQL API can't change, or really any code in<br />
>>> underneath any existing SQL functions.<br />
>>>However, I can implement the function as a completely additive thing (and<br />
>>> in fact have), so it affects the stability of existing functions not at all.<br />
>>> And I can leave the SQL API alone, and simple ship the CREATE FUNCTION code<br />
>>> directly to the client.<br />
>>><br />
>>>http://trac.osgeo.org/postgis/attachment/ticket/390/addmeasure.patch<br />
>>><br />
>>>They get the benefit of a quick turnaround on a new feature, we maintain<br />
>>> our contract with respect to leaving the API unchanged through minor<br />
>>> releases.<br />
>>>I'd like to apply this patch into stable branches so folks who want it can<br />
>>> have it, by running the CREATE FUNCTION code themselves.<br />
>>><br />
>>>Paul<br />
>>><br />
>>>--<br />
>>>Paul Ramsey<br />
>>>OpenGeo - http://opengeo.org<br />
>>>The secret sauce is called... PostGIS.<br />
>>><br />
>>>_______________________________________________<br />
>>>postgis-devel mailing list<br />
>>>postgis-devel@postgis.refractions.net<br />
>>>http://postgis.refractions.net/mailman/listinfo/postgis-devel<br />
>>><br />
>>><br />
>> _______________________________________________<br />
>> postgis-devel mailing list<br />
>> postgis-devel@postgis.refractions.net<br />
>> http://postgis.refractions.net/mailman/listinfo/postgis-devel<br />
>><br />
>><br />
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