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<div class=Section1><pre><font size=2 face="Courier New"><span
style='font-size:10.0pt'>Hi,<o:p></o:p></span></font></pre><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>I did not find the explanation of this question very satisfying:<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>><i><span
style='font-style:italic'> * Is there a way to convert a GeometryCollection returned by polygonize <o:p></o:p></span></i></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>><i><span
style='font-style:italic'> to a MultiPolygon? Is there any advantage to doing this?<o:p></o:p></span></i></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>Could you expand on possible ways of converting a GeometryCollection into a Multipolygon?<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>Thanks.<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>-James DeMichele<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>On Sat, Nov 12, 2005 at 03:04:36PM -0700, Charlie Savage wrote:<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>><i><span
style='font-style:italic'> Couple of questions about polygonize.<o:p></o:p></span></i></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>><i><span
style='font-style:italic'> <o:p></o:p></span></i></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>><i><span
style='font-style:italic'> * Why does it return a GeometryCollection instead of a MultiPolygon?<o:p></o:p></span></i></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>Because it's really a collection of polygons, not a MultiPolygon.<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>A MultiPolygon must meet certain constraints in order to be valid<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>(polygons must not intersect) and Polygonize doesn't try to enforce<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>this.<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>><i><span
style='font-style:italic'> * Is there a way to convert a GeometryCollection returned by polygonize <o:p></o:p></span></i></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>><i><span
style='font-style:italic'> to a MultiPolygon? Is there any advantage to doing this?<o:p></o:p></span></i></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>Check out the dump() and collect() functions.<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'>--strk;<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'> /"\ ASCII Ribbon Campaign<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'> \ / Respect for open standards<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'> X No HTML/RTF in email<o:p></o:p></span></font></pre><pre><font
size=2 face="Courier New"><span style='font-size:10.0pt'> / \ No M$ Word docs in email<o:p></o:p></span></font></pre>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=trebuchet style='margin:0in;margin-bottom:.0001pt'><b><font size=1
color="#677c94" face="Trebuchet MS"><span style='font-size:9.0pt;font-family:
"Trebuchet MS";color:#677C94;font-weight:bold'>James DeMichele </span></font></b><font
size=1 color=silver face="Trebuchet MS"><span style='font-size:9.0pt;
font-family:"Trebuchet MS";color:silver'>|</span></font><b><font size=1
color="#677c94" face="Trebuchet MS"><span style='font-size:9.0pt;font-family:
"Trebuchet MS";color:#677C94;font-weight:bold'> Software Engineer<o:p></o:p></span></font></b></p>
<p class=trebuchet style='margin:0in;margin-bottom:.0001pt'><font size=1
color="#93887c" face="Trebuchet MS"><span style='font-size:9.0pt;font-family:
"Trebuchet MS";color:#93887C'><a href="mailto:james.demichele@redfin.com">james.demichele@redfin.com</a>
</span></font><font size=1 color=silver face="Trebuchet MS"><span
style='font-size:9.0pt;font-family:"Trebuchet MS";color:silver'>|</span></font><font
size=1 color="#93887c" face="Trebuchet MS"><span style='font-size:9.0pt;
font-family:"Trebuchet MS";color:#93887C'> tel: 206.859.2853 </span></font><font
size=1 color=silver face="Trebuchet MS"><span style='font-size:9.0pt;
font-family:"Trebuchet MS";color:silver'>|</span></font><font size=1
color="#93887c" face="Trebuchet MS"><span style='font-size:9.0pt;font-family:
"Trebuchet MS";color:#93887C'> fax: 206.859.2941<o:p></o:p></span></font></p>
<p class=trebuchet style='margin:0in;margin-bottom:.0001pt'><font size=1
color="#93887c" face="Trebuchet MS"><span style='font-size:9.0pt;font-family:
"Trebuchet MS";color:#93887C'><o:p> </o:p></span></font></p>
<p class=trebuchet style='margin:0in;margin-bottom:.0001pt'><font size=1
color="#93887c" face="Trebuchet MS"><span style='font-size:8.5pt;font-family:
"Trebuchet MS";color:#93887C'>Redfin Corporation<o:p></o:p></span></font></p>
<p class=trebuchet style='margin:0in;margin-bottom:.0001pt'><st1:Street w:st="on"><st1:address
w:st="on"><font size=1 color="#93887c" face="Trebuchet MS"><span
style='font-size:8.5pt;font-family:"Trebuchet MS";color:#93887C'>710 2<sup>nd</sup>
Ave.</span></font></st1:address></st1:Street><font size=1 color="#93887c"
face="Trebuchet MS"><span style='font-size:8.5pt;font-family:"Trebuchet MS";
color:#93887C'><o:p></o:p></span></font></p>
<p class=trebuchet style='margin:0in;margin-bottom:.0001pt'><st1:address w:st="on"><st1:Street
w:st="on"><font size=1 color="#93887c" face="Trebuchet MS"><span
style='font-size:8.5pt;font-family:"Trebuchet MS";color:#93887C'>Suite</span></font></st1:Street><font
size=1 color="#93887c" face="Trebuchet MS"><span style='font-size:8.5pt;
font-family:"Trebuchet MS";color:#93887C'> 600</span></font></st1:address><font
size=1 color="#93887c" face="Trebuchet MS"><span style='font-size:8.5pt;
font-family:"Trebuchet MS";color:#93887C'><o:p></o:p></span></font></p>
<p class=trebuchet style='mso-margin-top-alt:0in;margin-right:0in;margin-bottom:
12.0pt;margin-left:0in'><st1:place w:st="on"><st1:City w:st="on"><font size=1
color="#93887c" face="Trebuchet MS"><span style='font-size:8.5pt;font-family:
"Trebuchet MS";color:#93887C'>Seattle</span></font></st1:City><font size=1
color="#93887c" face="Trebuchet MS"><span style='font-size:8.5pt;font-family:
"Trebuchet MS";color:#93887C'>, <st1:State w:st="on">WA</st1:State> <st1:PostalCode
w:st="on">98104</st1:PostalCode></span></font></st1:place><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><U1:STREET u2:st="on"><U1:ADDRESS u2:st="on"> <o:p></o:p></span></font></p>
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