On Sunday 05 February 2006 09:16 am, Bill Binko wrote: > On Fri, 2006-02-03 at 11:40 -0800, Dylan Beaudette wrote: > > I was just working on this last night: > > http://casoilresource.lawr.ucdavis.edu/drupal/node/172 > > > > check out the source for v.kernel in GRASS > > Dylan, > This is an excellent example of what I'm trying to achieve. Here are > some quick thoughts about what you've shown: > > 1) How would you publish this "live" to the web? Do you know how to > integrate v.kernel to push its output to mapserver directly? I know > there are tools to push GRASS output through GDAL, and I suspect that > that could be daisy chained into mapserver, but I'd like someone's > opinion who's actually done this. If there's an example (anybody?) or > HOWTO of how to leverage GRASS this way? >
Hi Bill, Here is a quick link to the GRASS site, on how to get a GRASS-Mapserver application running: http://grass.itc.it/start.html towards the bottom of the page, there is a link to a project from some time ago which called GRASS directly using PHP: essentially setting up the GRASS environmental variables, and then running the appropriate commands via system(). > 2) What is the performance of v.kernel. For example, I'll have 30-100K > points over the state of florida. For a zoomed out view, how long would > that take to draw? Perhaps a better question would be, what is the > order of complexity of the approach taken by GRASS. Well- it is resolution dependant. The map made with v.kernel is of an area close to 27k acres, and at a resolution of 10m it took about 5 minutes. However, at a resolution of 100m it only a took a couple seconds. > 3) Unfortunately, because I may want to integrate this into Mapserver, I > can't quite look at the GRASS source on this. More specifically, I > can't copy it since it's GPL into Mapserver, which is BSD and then > distribute it. Now: I may choose to simply write code to call GRASS > externally, but I wouldn't need to explore the source for that. See the PHP example for calling an install of a GRASS directly. > I will however, get GRASS 6 up and running here so that I can explore > it. Thanks for the pointer. You bet. Let me know how it turns out. Cheers, -- Dylan Beaudette Soils and Biogeochemistry Graduate Group University of California at Davis 530.754.7341
