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<DIV id=idOWAReplyText66828>
<DIV><FONT color=#000000 size=3 face="Times New Roman">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 color=#000000 size=3 face="Times New Roman">Regards,</FONT></DIV></DIV>
<DIV id=idSignature87837>
<DIV><FONT size=2 face="Courier New"><FONT size=3 face="Times New Roman">Juan Lucas Domínguez Rubio<BR></FONT>---</FONT></DIV>
<DIV><FONT size=2 face="Courier New"><FONT size=2 face="Courier New"><FONT size=2 face="Courier New">Prodevelop SL, Valencia (España)</FONT></DIV>
<DIV>
<DIV><FONT size=2 face="Courier New">Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR></FONT><A href="http://www.prodevelop.es/"><FONT size=2 face="Courier New">http://www.prodevelop.es</FONT></A><BR><FONT size=2 face="Courier New">---</FONT></DIV></FONT></DIV></FONT></DIV>
<DIV><BR>
<HR>
<FONT size=2 face=Tahoma><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 size=2 face=Arial>Dear Juan,</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>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 size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>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 size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Best wishes,</FONT></DIV>
<DIV><FONT size=2 face=Arial>Sal</FONT></DIV>
<BLOCKQUOTE style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="FONT: 10pt arial; BACKGROUND: #e4e4e4"><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 color=#000000 size=3 face="Times New Roman">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 color=#000000 size=3 face="Times New Roman"></FONT> </DIV></DIV>
<DIV id=idSignature15203>
<DIV><FONT size=2 face="Courier New"><FONT size=3 face="Times New Roman">Juan Lucas Domínguez Rubio<BR></FONT>---</FONT></DIV>
<DIV><FONT size=2 face="Courier New"><FONT size=2 face="Courier New"><FONT size=2 face="Courier New">Prodevelop SL, Valencia (España)</FONT></DIV>
<DIV>
<DIV><FONT size=2 face="Courier New">Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR></FONT><A href="http://www.prodevelop.es/"><FONT size=2 face="Courier New">http://www.prodevelop.es</FONT></A><BR><FONT size=2 face="Courier New">---</FONT></DIV></FONT></DIV></FONT></DIV>
<DIV><BR>
<HR>
<FONT size=2 face=Tahoma><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 size=2 face=Arial>Dear All,</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>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 size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>All the best,</FONT></DIV>
<DIV><FONT size=2 face=Arial>Sal Garfi</FONT></DIV></DIV>
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