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<p class=MsoNormal><span style='color:#1F497D'>Robert, returning to the
original issue: what is the meaning of PointX(geometry, ‘</span><span
style='color:#1F497D'>end’) for a polygon?<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Dan.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
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<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
fdo-internals-bounces@lists.osgeo.org [mailto:fdo-internals-bounces@lists.osgeo.org]
<b>On Behalf Of </b>Robert Fortin<br>
<b>Sent:</b> Tuesday, November 04, 2008 2:46 PM<br>
<b>To:</b> FDO Internals Mail List<br>
<b>Subject:</b> RE: [fdo-internals] Request review of RFC 28
-AddStart/EndExpressionFunctions<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='color:#003300'>I think there was plenty of good
idea of how far we can go with these kind of functions. But, trying to go
back to the original issue we were trying to resolve by RFC-28 which is simply
to get the coordinates values for the first and last point…<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#003300'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#003300'>I think Romy has an interesting
proposal that makes the function evolutive over time and avoid over populating
the list of functions with new names each time we think of a new possibility.
It also makes it clear that it is about the points on the geometry and not
computed point as other functions like MidX or CentroidX would be (but
that a matter for another debate).<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#003300'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#003300'>I was thinking of even
rationalizing it further (by adding another enumeration parameter to indicate
x,y and z – we forgot about “m” by the way!) but I think the
name of the function PointX, PointY and PointZ are just clear enough.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#003300'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#003300'>Can we go for that as far as the
RFC is concerned?<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#003300'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#003300'>RF<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#003300'><o:p> </o:p></span></p>
<div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
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<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
fdo-internals-bounces@lists.osgeo.org
[mailto:fdo-internals-bounces@lists.osgeo.org] <b>On Behalf Of </b>Romica
Dascalescu<br>
<b>Sent:</b> Tuesday, November 04, 2008 11:27 AM<br>
<b>To:</b> FDO Internals Mail List<br>
<b>Subject:</b> RE: [fdo-internals] Request review of RFC 28
-AddStart/EndExpressionFunctions<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='color:#1F497D'>Hi,<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>A different approach is to
create functions which takes a geometry and an enumeration, this way each
provider can implement all cases or just a few of them, e.g.:<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>PointX(geom, enum)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>PointY(geom, enum)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>PointZ(geom, enum)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Where enum can be:
‘start’, ‘end’, ‘min’, ‘max’,
‘centroid’, …<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>For now we may implement just a
few of them (start, end) and in the future we could implement more cases.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Romy.<o:p></o:p></span></p>
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