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

[Markus Metz]

On Wed, Jul 25, 2012 at 5:59 AM, Hamish <hamish_b at yahoo.com> wrote:
> 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.

So it is better to use the spearfish location but a raster name from
the NC dataset and let users hunt around for an exact name that does
not exist? Sorry for the provocation, but that is the status quo.
IMHO, if there are screenshots in the quickstart, the instructions
should be such that the screenshots can be reproduced, otherwise users
might be confused that their results do not look like the provided
screenshots (easy reproducibility of results is not such a bad idea).

You could add a short half-sentence to the very first paragraph, e.g.
"... some slight adjustments may be needed for the NC dataset, e.g. by
using elevation at PERMANENT instead of elevation.10m at PERMANENT."

>
>> 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.

If the quickstart is supposed to target beginners, it would IMHO be
better to have matching examples and screenshots to avoid confusion.

Markus