<html><body><div style="color:#000; background-color:#fff; font-family:tahoma, new york, times, serif;font-size:10pt"><div style="font-family: tahoma, 'new york', times, serif; font-size: 10pt; "><span>Solved</span></div><div style="font-family: tahoma, 'new york', times, serif; font-size: 10pt; "><span><br></span></div><div style="font-family: tahoma, 'new york', times, serif; font-size: 10pt; "><span>Thank you. </span></div><div><span><font size="2">I found good solutions. .</font></span></div><div><span><font size="2">gvSIG is part of it. It delivers straightforwardly the minimum circle and minimum rectangle for a group of points (the vertices) per class of points (number of polygon). </font></span></div><div style="font-family: tahoma, 'new york', times, serif; font-size: 10pt; "><span><br></span></div><div style="font-family: tahoma, 'new york', times, serif; font-size: 10pt; "><span>Cheers,</span></div><div style="font-family:
tahoma, 'new york', times, serif; font-size: 10pt; "><span>Marco</span></div><div style="font-family: tahoma, 'new york', times, serif; font-size: 10pt; "><br></div> <div style="font-size: 10pt; font-family: tahoma, 'new york', times, serif; "> <div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "> <div dir="ltr"> <font size="2" face="Arial"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> Margherita Di Leo <diregola@gmail.com><br> <b><span style="font-weight: bold;">To:</span></b> Marco <marco_gjv@ymail.com> <br><b><span style="font-weight: bold;">Cc:</span></b> "grass-user@lists.osgeo.org" <grass-user@lists.osgeo.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, June 7, 2012 1:26 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [GRASS-user] r.basin ? for plane geometry of polygon shapefiles<br> </font> </div> <br>
<meta http-equiv="x-dns-prefetch-control" content="off"><div id="yiv1637318008">Marco,<br><br><div class="yiv1637318008gmail_quote">On Thu, Jun 7, 2012 at 1:15 PM, Marco <span dir="ltr"><<a rel="nofollow" ymailto="mailto:marco_gjv@ymail.com" target="_blank" href="mailto:marco_gjv@ymail.com">marco_gjv@ymail.com</a>></span> wrote:<br><blockquote class="yiv1637318008gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div><div style="font-size: 10pt; font-family: tahoma, 'new york', times, serif; "><div><span>Hi Margherita,</span></div><div><br><span></span></div><div><span>Grazie. Its not related to hydrology. I just want to get some shape indexes to characterize networks of polygons (periglacial patterned ground).<br>
</span></div><div><span></span><span>I came to your Grass Add-on because the indexes used in 2D basin morphometry are really adequate to characterize each individual polygon.<br></span></div><div><span><br></span></div><div>
<span>I have already used SAGA GIS and GVSig, which automatically supply shape parameters relating the perimeter of the polygon to its area in various ways. And thatīs already fine information. <br></span></div><div><span>From that I know if the polygon is more elongated or more circular. And maybe more information wonīt add to much... But I still would like to try. Mainly because of the indexes
which grab the axis and which relate the polygon to and ideal shape. </span></div><div><br><span></span></div><div><span>Maybe I should focus on doing one thing at a time: 1) axis calculation; and 2) deriving the ideal shape from the centroid of the polygon.</span><span> Then Iīd have great information. <br>
</span></div></div></div></blockquote><div><br></div><div>Have you seen v.to.db[1]? It allows you to calculate some parameters such as area, perimeter, compactness, fractal dimension, etc. </div><blockquote class="yiv1637318008gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div><div style="font-size: 10pt; font-family: tahoma, 'new york', times, serif; "><div><span></span></div><div><span><br></span></div><div><span>My next step is to go inside you python code (of which I know little) and try to extract the relevant pieces. </span></div>
</div></div></blockquote><div><br></div><div>The code is quite self-explanatory and the formulas are very simple so that you could also calculate some parameters in a spreadsheet, anyways if you need further information don't hesitate to ask. </div>
<blockquote class="yiv1637318008gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div style="font-size: 10pt; font-family: tahoma, 'new york', times, serif; "><div><br><span></span></div><div><span>Thank you.</span></div>
<div><span>Marco<br></span></div><div><span>(gonna start a MSc <font><font face="Arial">related to cryosphere geomorphology next Fall)</font></font></span></div></div></div></blockquote><div><br></div><div>Congrats ;-)</div>
<div><br></div><div>ciao madi</div><div> </div></div><div>[1] http://grass.osgeo.org/gdp/html_grass64/v.to.db.html</div>-- <br>Dr. Margherita Di Leo<br>
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