very cool. i hope to contribute where i can.<br><br><div><span class="gmail_quote">On 6/19/06, <b class="gmail_sendername">Jonathan Greenberg</b> <<a href="mailto:jgreenberg@arc.nasa.gov">jgreenberg@arc.nasa.gov</a>> wrote:
</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Grassers:<br><br> I'll get the table started ASAP, but I'm busy over the next few
<br>weeks -- if someone wants to get it going on the wiki feel free, otherwise<br>I'll get to it when can. I was thinking a table at the top of the page with<br>the headings "Software (ARCINFO/ArcMap/ArcView)","ESRI command/feature",
<br>"GRASS command(s)", and an anchor-link to a set of headers below the table<br>that have a discussion of the similarities/differences, and how to replicate<br>the arc process "perfectly" if possible. The table and subsequent
<br>discussion should be alphabetized by the ARC software and then by the arc<br>command. Here's an example/possible entry that could be included:<br><br>***<br><br>Table entries:<br>Software: ARC/INFO (ARC)<br>ESRI command/feature: LATTICESPOT
<br>GRASS command(s): v.what.rast<br><br>Discussion entry:<br>LATTICESPOT<br>LATTICESPOT has a nearly perfect translation to v.what.rast as follows:<br>LATTICESPOT <in_lattice> <in_cover> {spot_item} {z_factor}
<br> translates to:<br>v.what.rast vector=<in_cover> raster=<in_lattice> layer=layer<br>column={spot_item}<br><br>Discrepancies:<br> -{spot_item} defaults to "SPOT" for LATTICESPOT, but must be
<br>explicitly defined for v.what.rast<br> -{z_factor} must be applied the GRASS vector database<br>after-the-fact.<br> -LATTICESPOT performs a bilinear interpolation to assign raster<br>values to the output vector, whereas
v.what.rast uses nearest neighbor.<br><br>***<br><br>One of the goals of this wiki page, I think, would be to minimize or remove<br>all discrepancies. This is where the use of a wiki really helps: power<br>users of GRASS can offer ways that people like me (who are basically
<br>newbies) can't figure out. For instance, how can we solve the z_factor<br>discrepancy -- how do I multiply a GRASS vector column by a fixed value?<br>This would remove that discrepancy between the ARC and GRASS.<br><br>
--j<br><br>--<br><br>Jonathan A. Greenberg, PhD<br>NRC Research Associate<br>NASA Ames Research Center<br>MS 242-4<br>Moffett Field, CA 94035-1000<br>Phone: 415-794-5043<br>AIM: jgrn3007<br>MSN: <a href="mailto:jgrn3007@hotmail.com">
jgrn3007@hotmail.com</a><br><br><br>_______________________________________________<br>grassuser mailing list<br><a href="mailto:grassuser@grass.itc.it">grassuser@grass.itc.it</a><br><a href="http://grass.itc.it/mailman/listinfo/grassuser">
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