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<DIV id=idOWAReplyText63349>
<DIV><FONT face="Times New Roman" color=#000000 size=3>Hello, great!</FONT></DIV>
<DIV> </DIV>
<DIV>An interesting result:</DIV>
<DIV> </DIV>
<DIV>This KML:</DIV>
<DIV> </DIV>
<DIV>===================================================<BR><kml xmlns="<A href="http://earth.google.com/kml/2.1">http://earth.google.com/kml/2.1</A>"><BR><Document><name>equator degree</name><BR><Region><LatLonAltBox><BR><north>0.0</north><south>0.0</south><BR><east>-119.0</east><west>-120.0</west><BR><minAltitude>0.0</minAltitude><BR><maxAltitude>0.0</maxAltitude><BR></LatLonAltBox></Region><BR><Placemark id="0"><BR><LineString><coordinates>-120,0.0 -119.0,0.0 </coordinates></LineString><BR><ExtendedData></ExtendedData></Placemark><BR></Document><BR></kml><BR>===================================================</DIV>
<DIV> </DIV>
<DIV>is a simple line in the Pacific Ocean from (120W, 0N) to (119W, 0N), so its length should be:</DIV>
<DIV> </DIV>
<DIV>L = 2 x pi x R / 360 = 111,319.49 m</DIV>
<DIV> </DIV>
<DIV>with R = 6378137 (WGS84 ellipsoid max radius)</DIV>
<DIV> </DIV>
<DIV>but Google Earth says its length is 111,195.1 m</DIV>
<DIV> </DIV>
<DIV>So apparently Google Earth systematically provides a value with an error of about -0.1%</DIV>
<DIV> </DIV>
<DIV>Regards,</DIV>
<DIV><FONT face="Times New Roman" color=#000000 size=3></FONT> </DIV></DIV>
<DIV id=idSignature96458>
<DIV><FONT face="Courier New" size=2><FONT face="Times New Roman" size=3>Juan Lucas Domínguez Rubio<BR></FONT>---</FONT></DIV>
<DIV><FONT face="Courier New" size=2><FONT face="Courier New" size=2><FONT face="Courier New" size=2>Prodevelop SL, Valencia (España)</FONT></DIV>
<DIV>
<DIV><FONT face="Courier New" size=2>Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR></FONT><A href="http://www.prodevelop.es/"><FONT face="Courier New" size=2>http://www.prodevelop.es</FONT></A><BR><FONT face="Courier New" size=2>---</FONT></DIV></FONT></DIV></FONT></DIV>
<DIV><BR>
<HR>
<FONT face=Tahoma size=2><B>De:</B> gvsig_internacional-bounces@listserv.gva.es en nombre de Sal Garfi<BR><B>Enviado el:</B> mar 09/11/2010 10:25<BR><B>Para:</B> Users and Developers mailing list<BR><B>Asunto:</B> Re: [Gvsig_english] determining length of lines in a polyline layer<BR></FONT><BR></DIV>
<DIV>
<DIV><FONT face=Arial size=2>Hello Juan,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>It appears that I should get an award for sillyness! I mistakenly selected the wrong projection when I loaded my shape file into gvSIG. I just highlighted the wrong projection in my list of recently used projections when I created a new view to work in!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks so much for your efforts and help,</FONT></DIV>
<DIV><FONT face=Arial size=2>Sal garfi</FONT></DIV>
<BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial"><B>From:</B> <A title=jldominguez@prodevelop.es href="mailto:jldominguez@prodevelop.es">Juan Lucas Dominguez Rubio</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=gvsig_internacional@listserv.gva.es href="mailto:gvsig_internacional@listserv.gva.es">Users and Developers mailing list</A> ; <A title=gvsig_internacional@listserv.gva.es href="mailto:gvsig_internacional@listserv.gva.es">Users and Developers mailing list</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, November 09, 2010 12:16 AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [Gvsig_english] determining length of lines in a polyline layer</DIV>
<DIV><BR></DIV>
<DIV id=idOWAReplyText66828>
<DIV><FONT face="Times New Roman" color=#000000 size=3>Hello, Sal:</FONT></DIV>
<DIV> </DIV>
<DIV>Using the function perimeter() with the field calculator (not Sextante) in your shapefile, I get these values:</DIV>
<DIV> </DIV>
<DIV>d1: 31918.91 m</DIV>
<DIV>d2: 3647.84 m</DIV>
<DIV>d3: 12396.15 m</DIV>
<DIV> </DIV>
<DIV>while Google Earth says:</DIV>
<DIV> </DIV>
<DIV>d1: 31883 m<BR>d2: 3644 m<BR>d3: 12382 m</DIV>
<DIV> </DIV>
<DIV>The difference is again a bit more than 0.1 %</DIV>
<DIV> </DIV>
<DIV>How did you compute the fields "Length" and "Length2" ?</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV><FONT face="Times New Roman" color=#000000 size=3>Regards,</FONT></DIV></DIV>
<DIV id=idSignature87837>
<DIV><FONT face="Courier New" size=2><FONT face="Times New Roman" size=3>Juan Lucas Domínguez Rubio<BR></FONT>---</FONT></DIV>
<DIV><FONT face="Courier New" size=2><FONT face="Courier New" size=2><FONT face="Courier New" size=2>Prodevelop SL, Valencia (España)</FONT></DIV>
<DIV>
<DIV><FONT face="Courier New" size=2>Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR></FONT><A href="http://www.prodevelop.es/"><FONT face="Courier New" size=2>http://www.prodevelop.es</FONT></A><BR><FONT face="Courier New" size=2>---</FONT></DIV></FONT></DIV></FONT></DIV>
<DIV><BR>
<HR>
<FONT face=Tahoma size=2><B>De:</B> gvsig_internacional-bounces@listserv.gva.es en nombre de Sal Garfi<BR><B>Enviado el:</B> lun 08/11/2010 13:57<BR><B>Para:</B> Users and Developers mailing list<BR><B>Asunto:</B> Re: [Gvsig_english] determining length of lines in a polyline layer<BR></FONT><BR></DIV>
<DIV>
<DIV><FONT face=Arial size=2>Dear Juan,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Yes, you are right to correct me. The gvSIG distance is ca 5% less than the Google Earth distance, so I'm attaching the the original kml file and the shape file which includes two 'length' fields. The first length field was created using Sextante, while the 'Length 2' field was created by the length determination facility in gvSIG.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>You'll also notice that the kml file shows a very small part of the infamous complex of berms that have been created by Morocco in Western Sahara. I've already digitised, in Google Earth, the entirety of the berms and I now want to calculate their lengths and input them into gvSIG for further analysis. This is part of my PhD research on the war in Western Sahara.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Best wishes,</FONT></DIV>
<DIV><FONT face=Arial size=2>Sal</FONT></DIV>
<BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial"><B>From:</B> <A title=jldominguez@prodevelop.es href="mailto:jldominguez@prodevelop.es">Juan Lucas Dominguez Rubio</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=gvsig_internacional@listserv.gva.es href="mailto:gvsig_internacional@listserv.gva.es">Users and Developers mailing list</A> ; <A title=gvsig_internacional@listserv.gva.es href="mailto:gvsig_internacional@listserv.gva.es">Users and Developers mailing list</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, November 08, 2010 12:18 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [Gvsig_english] determining length of lines in a polyline layer</DIV>
<DIV><BR></DIV>
<DIV id=idOWAReplyText25026>
<DIV><FONT face="Times New Roman" color=#000000 size=3>Hello, Sal.</FONT></DIV>
<DIV> </DIV>
<DIV>"95% less than" means "20 times less than", actually.</DIV>
<DIV> </DIV>
<DIV>Do you mean "5% less than"? (you expected 100 and got 95)</DIV>
<DIV> </DIV>
<DIV>I have made a test with the attached shapefile and:</DIV>
<DIV> </DIV>
<DIV>
<DIV>gvSIG says it's length is 50.12 m
<DIV>Google Earth says it's length is 50.06 m</DIV>
<DIV> </DIV>
<DIV>The difference is about 0.12 %.</DIV>
<DIV> </DIV>
<DIV>Can you send your example?</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>Regards,</DIV></DIV></DIV>
<DIV><FONT face="Times New Roman" color=#000000 size=3></FONT> </DIV></DIV>
<DIV id=idSignature15203>
<DIV><FONT face="Courier New" size=2><FONT face="Times New Roman" size=3>Juan Lucas Domínguez Rubio<BR></FONT>---</FONT></DIV>
<DIV><FONT face="Courier New" size=2><FONT face="Courier New" size=2><FONT face="Courier New" size=2>Prodevelop SL, Valencia (España)</FONT></DIV>
<DIV>
<DIV><FONT face="Courier New" size=2>Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR></FONT><A href="http://www.prodevelop.es/"><FONT face="Courier New" size=2>http://www.prodevelop.es</FONT></A><BR><FONT face="Courier New" size=2>---</FONT></DIV></FONT></DIV></FONT></DIV>
<DIV><BR>
<HR>
<FONT face=Tahoma size=2><B>De:</B> <A href="mailto:gvsig_internacional-bounces@listserv.gva.es">gvsig_internacional-bounces@listserv.gva.es</A> en nombre de Sal Garfi<BR><B>Enviado el:</B> lun 08/11/2010 12:31<BR><B>Para:</B> Users and Developers mailing list<BR><B>Asunto:</B> [Gvsig_english] determining length of lines in a polyline layer<BR></FONT><BR></DIV>
<DIV>
<DIV><FONT face=Arial size=2>Dear All,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I have recently digitised linear features in Google earth that I have converted from kml format to shape files. I wanted to tabulate the total distances of these lines in gvSIG so I used the available facility in vector line tools in Sextante. However, the distances were on average 95% less than the distances noted in the features' properties in Google Earth. I then used gvSig's own facility for determining lengths of polylines and these were the same as those determined in Sextante. I'm working in WGS84 - so what could be causing the differences? And which system is correct, Google Earth or gvSIG? </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>All the best,</FONT></DIV>
<DIV><FONT face=Arial size=2>Sal Garfi</FONT></DIV></DIV>
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