<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:p="urn:schemas-microsoft-com:office:powerpoint" xmlns:a="urn:schemas-microsoft-com:office:access" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882" xmlns:rs="urn:schemas-microsoft-com:rowset" xmlns:z="#RowsetSchema" xmlns:b="urn:schemas-microsoft-com:office:publisher" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:odc="urn:schemas-microsoft-com:office:odc" xmlns:oa="urn:schemas-microsoft-com:office:activation" xmlns:html="http://www.w3.org/TR/REC-html40" xmlns:q="http://schemas.xmlsoap.org/soap/envelope/" xmlns:D="DAV:" xmlns:x2="http://schemas.microsoft.com/office/excel/2003/xml" xmlns:ois="http://schemas.microsoft.com/sharepoint/soap/ois/" xmlns:dir="http://schemas.microsoft.com/sharepoint/soap/directory/" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" xmlns:dsp="http://schemas.microsoft.com/sharepoint/dsp" xmlns:udc="http://schemas.microsoft.com/data/udc" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:sub="http://schemas.microsoft.com/sharepoint/soap/2002/1/alerts/" xmlns:ec="http://www.w3.org/2001/04/xmlenc#" xmlns:sp="http://schemas.microsoft.com/sharepoint/" xmlns:sps="http://schemas.microsoft.com/sharepoint/soap/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:udcxf="http://schemas.microsoft.com/data/udc/xmlfile" xmlns:wf="http://schemas.microsoft.com/sharepoint/soap/workflow/" xmlns:mver="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns:mrels="http://schemas.openxmlformats.org/package/2006/relationships" xmlns:ex12t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:ex12m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:Z="urn:schemas-microsoft-com:" xmlns:st="&#1;" xmlns="http://www.w3.org/TR/REC-html40">

<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<style>
<!--
 /* Font Definitions */
 @font-face
        {font-family:Calibri;
        panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
        {font-family:Tahoma;
        panose-1:2 11 6 4 3 5 4 4 2 4;}
 /* Style Definitions */
 p.MsoNormal, li.MsoNormal, div.MsoNormal
        {margin:0in;
        margin-bottom:.0001pt;
        font-size:11.0pt;
        font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
        {mso-style-priority:99;
        color:blue;
        text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
        {mso-style-priority:99;
        color:purple;
        text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
        {mso-style-priority:34;
        margin-top:0in;
        margin-right:0in;
        margin-bottom:0in;
        margin-left:.5in;
        margin-bottom:.0001pt;
        font-size:11.0pt;
        font-family:"Calibri","sans-serif";}
span.EmailStyle18
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:windowtext;}
span.EmailStyle19
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle20
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#993366;}
span.EmailStyle21
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle22
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle23
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle24
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle25
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle26
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle27
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle28
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle29
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle30
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#003300;}
span.EmailStyle31
        {mso-style-type:personal-reply;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
.MsoChpDefault
        {mso-style-type:export-only;
        font-size:10.0pt;}
@page Section1
        {size:8.5in 11.0in;
        margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
        {page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
 <o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
 <o:shapelayout v:ext="edit">
  <o:idmap v:ext="edit" data="1" />
 </o:shapelayout></xml><![endif]-->
</head>

<body lang=EN-US link=blue vlink=purple>

<div class=Section1>

<p class=MsoNormal><span style='color:#1F497D'>Robert, returning to the
original issue:&nbsp; what is the meaning of PointX(geometry, &#8216;</span><span
style='color:#1F497D'>end&#8217;) for a polygon?<o:p></o:p></span></p>

<p class=MsoNormal><span style='color:#1F497D'><o:p>&nbsp;</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>&nbsp;</o:p></span></p>

<p class=MsoNormal><span style='color:#1F497D'><o:p>&nbsp;</o:p></span></p>

<div>

<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>&nbsp;</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.&nbsp; 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&#8230;<o:p></o:p></span></p>

<p class=MsoNormal><span style='color:#003300'><o:p>&nbsp;</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&nbsp; (but
that a matter for another debate).<o:p></o:p></span></p>

<p class=MsoNormal><span style='color:#003300'><o:p>&nbsp;</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 &#8211; we forgot about &#8220;m&#8221; 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>&nbsp;</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>&nbsp;</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>&nbsp;</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>&nbsp;</o:p></span></p>

<div>

<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>&nbsp;</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>&nbsp;</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>&nbsp;</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>&nbsp;</o:p></span></p>

<p class=MsoNormal><span style='color:#1F497D'>Where enum can be:
&#8216;start&#8217;, &#8216;end&#8217;, &#8216;min&#8217;, &#8216;max&#8217;,
&#8216;centroid&#8217;, &#8230;<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>&nbsp;</o:p></span></p>

<p class=MsoNormal><span style='color:#1F497D'>Romy.<o:p></o:p></span></p>

</div>

</div>

</body>

</html>