[GRASS-user] please help review osgeo live dvd summary docs

[Hamish]

Markus Metz wrote:
> An example for vector processing using the basins raster
> created in the previous step:
> 
> 1) convert the basins to vector areas with r.to.vect -v feature=area
> 2) load average elevation for each basin to the attribute table with
> v.rast.stats
> 3) assign the color table of the raster elevation using average
> elevation values to the basins vector with v.colors column=elev_mean
> raster=elevation.10m
> 4) display the vector using the colors in GRASSRGB

thanks, that leads through nicely. Now added, with some short notes
about the attribute table manager, cartographic composer, and graphical
modeler under "other things to try".

http://grass.osgeo.org/wiki/Quick_wxGUI_tutorial#Vector_modules
http://adhoc.osgeo.osuosl.org/livedvd/docs/en/quickstart/grass_quickstart.html

> BTW, there is no raster map named 'elevation' in the spearfish
> dataset, but e.g. 'elevation.10m' as seen in one of the screenshots in
> the quickstart. This should be corrected throughout the quickstart.

I know, I was trying to make the instructions generic enough to work
with either of the two datasets. I figured those using Spearfish would
see the .dem and .10m and figure out that they should pick one, but
those running in NC would be hunting around for an exact name which
didn't exist.

Due to severe space limitations on the disc I'm continually concerned
about having to remove the NC dataset, or cut it down to Helena's 40mb
set. We already ship geotiffs and shapefiles of the same maps as part of
the OSGeo Educational dataset for use by all of the 40 or so projects
contributing to the disc & their workshops, tutorials, etc. If the
instructions are vague enough the quickstart docs might survive an
upheaval in the available data. :)

> It seems that the basins in 'Watersheds and streams' were
> created with the minimum size of the exterior watershed basin threshold
> set to 100000 cells, not 10000 cells (missed a zero).

It's not a typo, I just ran it for elevation.dem not elevation.10m. Using
elevation.10m with a threshold of 10000 cells doesn't match the screenshot
but is not so bad, so just try to pick something in the middle and stay
loose.

> > In addition, on the disc the QGIS-GRASS bridge is broken because
> > of this bug:
> >   http://hub.qgis.org/issues/2947
> >   https://trac.osgeo.org/osgeo/ticket/868
> 
> The live dvd could use sextante for QGIS to access GRASS functionality.
> An added bonus would be that sextante has bindings to several GIS
> engines, one of them being GRASS, but others should also be already
> available on the live dvd.

I believe Alex is working on that right now. Ideally we'll have lots of
ways to flow between GRASS and QGIS and R and PostGIS all setup and
working. helpers & testers are most welcome! IRC: #osgeolive on Freenode
or the live-demo at o.o mailing list.


Hamish