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<DIV dir=ltr align=left><SPAN class=502383513-02042007><FONT face=Arial
color=#0000ff size=2>Its whatever the metric of your r.geometry field so if
that is in degrees then yes it would be in degrees.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=502383513-02042007><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=502383513-02042007><FONT face=Arial
color=#0000ff size=2>Thanks,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=502383513-02042007><FONT face=Arial
color=#0000ff size=2>Regina</FONT></SPAN></DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B>
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <B>On Behalf Of </B>Pedro
Doria Meunier<BR><B>Sent:</B> Monday, April 02, 2007 9:32 AM<BR><B>To:</B>
'PostGIS Users Discussion'<BR><B>Subject:</B> RE: [postgis-users] 10 closest
units<BR><B>Importance:</B> High<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV class=Section1>
<P class=MsoNormal><SPAN style="COLOR: #1f497d">Regina,<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN style="COLOR: #1f497d"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: #1f497d">You’re simply an
angel! Thank you!<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US
style="COLOR: #1f497d"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: #1f497d">Just one
question:<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: #1f497d">The
expand(rc.agg_geometry, 0.5) uses *<B>degrees</B>*, right?<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US
style="COLOR: #1f497d"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: #1f497d">All the
best,<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US
style="COLOR: #1f497d">Pedro.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US
style="COLOR: #1f497d"><o:p> </o:p></SPAN></P>
<DIV>
<DIV
style="BORDER-RIGHT: medium none; PADDING-RIGHT: 0cm; BORDER-TOP: #b5c4df 1pt solid; PADDING-LEFT: 0cm; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; PADDING-TOP: 3pt; BORDER-BOTTOM: medium none">
<P class=MsoNormal><B><SPAN lang=EN-US
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Tahoma','sans-serif'">From:</SPAN></B><SPAN
lang=EN-US style="FONT-SIZE: 10pt; FONT-FAMILY: 'Tahoma','sans-serif'">
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <B>On Behalf Of </B>Obe,
Regina<BR><B>Sent:</B> segunda-feira, 2 de Abril de 2007 13:43<BR><B>To:</B>
PostGIS Users Discussion<BR><B>Subject:</B> RE: [postgis-users] 10 closest
units<o:p></o:p></SPAN></P></DIV></DIV>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: 'Arial','sans-serif'">I'm not
sure how slow this would be depending on how many line segments you have by
name, but it seems the most speedy to write. Basically I think you want to
collect all your roads of N17 into a single geometry so that you can then apply
a single distance check call.</SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'"><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'"> <o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: 'Arial','sans-serif'">So
something like</SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'"><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'"> <o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: blue">select u.friendly_name,
distance(transform(u.curr_location, 32628), <o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US
style="COLOR: blue">transform(rc.agg_geometry,32628)) as thedistance
<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: blue">from (SELECT
collect(r.geometry) as agg_geometry FROM pt_mainland_roads r WHERE r.name =
'N17') rc, units as u <o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: blue">where
rc.agg_geometry && u.curr_location order by thedistance LIMIT
10;</SPAN><o:p></o:p></P>
<P class=MsoNormal> <o:p></o:p></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: blue">If you have some units
that are not in the bounding box of a road that would be in the top 10, then you
may want to change your where clause to</SPAN><SPAN
lang=EN-US><o:p></o:p></SPAN></P>
<P class=MsoNormal> <SPAN lang=EN-US><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: blue">expand(rc.agg_geometry,
<somevalue>)&& u.curr_location </SPAN><SPAN
lang=EN-US><o:p></o:p></SPAN></P>
<P class=MsoNormal> <SPAN lang=EN-US><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: blue">Hope that
helps,</SPAN><SPAN lang=EN-US><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US style="COLOR: blue">Regina</SPAN><SPAN
lang=EN-US><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'"><o:p> </o:p></SPAN></P>
<DIV class=MsoNormal style="TEXT-ALIGN: center" align=center><SPAN lang=EN-US
style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'">
<HR align=center width="100%" SIZE=2>
</SPAN></DIV>
<P class=MsoNormal style="MARGIN-BOTTOM: 12pt"><B><SPAN lang=EN-US
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Tahoma','sans-serif'">From:</SPAN></B><SPAN
lang=EN-US style="FONT-SIZE: 10pt; FONT-FAMILY: 'Tahoma','sans-serif'">
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <B>On Behalf Of </B>Pedro
Doria Meunier<BR><B>Sent:</B> Sunday, April 01, 2007 9:50 PM<BR><B>To:</B>
'PostGIS Users Discussion'<BR><B>Subject:</B> [postgis-users] 10 closest
units<BR><B>Importance:</B> High</SPAN><SPAN lang=EN-US
style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'"><o:p></o:p></SPAN></P>
<P class=MsoNormal>Hi All,<o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal><SPAN lang=EN-US>@Regina:<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>Remember you helped me with the 10 closest
units to a given point? This was it:<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>(original layers srid==4326 – I want
*<B>meters</B>* so the transform at play)<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>SELECT u.id, u.friendly_name,
u.curr_location, t.oid, distance(transform(u.curr_location,32628),
transform(t.geometry, 32628)) AS thedistance, u.mobile FROM units AS u, (SELECT
roads.oid, roads.geometry FROM roads WHERE name=’N17’ LIMIT 1) AS t
<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>ORDER BY thedistance LIMIT
10;<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>(this query returns the 1<SUP>st</SUP> found
line segment labelled ‘N17’ which is 68Kms away when the unit is actually 1.8
meters away from the closest line segment of the same
label)<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>@All<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>This actually returns the FIRST occurrence
of ‘N17’ (the sample).<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>This is *<B>NOT</B>* necessarily the closest
road to the unit’s current location.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>I’ve melted half-a-dozen neurons (mainly due
to tiredness at the time of this writing :] )trying to figure out how can I
implement the distance bit in the sub-query…<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>Given example for ONE
unit:<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>select u.friendly_name,
distance(transform(u.curr_location, 32628), <o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>transform(geometry,32628)) as thedistance
<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>from pt_mainland_roads as r, units as u
<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>where name='N17' AND u.curr_location
&& r.geometry order by thedistance LIMIT 1;<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>(this returns the correct
result)<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>So to summarize
things:<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>I need help with a query that returns the
*<B>FIRST TEN</B>* units to the *<B>closest given</B>* road.
<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>(Keep in mind that multiple line segments
with the same name exist – I need the closest)<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>Will try again tomorrow with a clear head
but in the meantime:<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>Any help would be most
appreciated!<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>Best regards,<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US>Pedro Doria Meunier.<o:p></o:p></SPAN></P>
<DIV class=MsoNormal style="TEXT-ALIGN: center" align=center><SPAN
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<HR align=center width="100%" SIZE=1>
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<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'"><o:p> </o:p></SPAN></P>
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