<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">This sounds very interesting, certainly I could see this really coming in handy when given a few thousand polygons of rivers and streams and asked to quickly output the centerlines... Finding centerlines of river/stream polygons may seem so simple for all this powerful computational equipment and software to clients, and perhaps it is to those who have higher math skills...<div><br></div><div><div><div>On 18-Jun-08, at 2:22 PM, Wolf Bergenheim wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><br>On 19.06.2008 00:01, Aurora Geomatics wrote:<br><blockquote type="cite">I wonder, is there a way to create a Voronoi diagram in GRASS?<br></blockquote><br>There is the v.voronoi module, which is also the subject of one of the Summer of Code projects this summer. I've been looking at an algorithm that creates Voronoi diagrams out of skeleton lines, but currently there is no direct support for skeleton lines in GRASS, as far as I can tell, perhaps if Martin P. gets interested he will develop this method and as a by-product a v.skeleton module, but that won't probably happen autumn if at all.<br><br>--Wolf<br></div></blockquote><br></div><div><br></div><div>Looks like some interesting material, I'll have a read though this, see what I can use out of it for my situation. I noticed the issue of the "Branching" outside the Centerline/Skeleton came up, I'll have to read deeper to see if or what the solution was for this issue.</div><div><br></div><div><blockquote type="cite">Have a look at this old page<br><br><a href="http://research.esd.ornl.gov/CRERP/DOCS/RIVERMI/P114.HTM">http://research.esd.ornl.gov/CRERP/DOCS/RIVERMI/P114.HTM</a><br><br>you could do the same thing in GRASS<br><br>Bill H.<br></blockquote></div><div><br></div><div><br></div><div>Thanks Tom, I must have miss spelled when I searched it in the GRASS manual. </div><div><br></div><blockquote type="cite">On Wed, Jun 18, 2008 at 02:01:56PM -0700, we recorded a bogon-computron collision of the <<a href="mailto:aurorageomatics@telus.net">aurorageomatics@telus.net</a>> flavor, containing:<br><blockquote type="cite"><br></blockquote><blockquote type="cite">I wonder, is there a way to create a Voronoi diagram in GRASS?<br></blockquote><blockquote type="cite"><br></blockquote><br>Yes. With v.voronoi.<br></blockquote><blockquote type="cite">-- <br>Tom Russo<br></blockquote><div><br></div><div><br></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Mars Sjoden</div><div>Aurora Geomatics</div><div><a href="mailto:aurorageo@telus.net">aurorageo@telus.net</a></div><div><a href="http://arorageo.blogspot.com/">http://arorageo.blogspot.com/</a></div></div></span></div></span></div></span></div></span> </div><br></div></body></html>