[GRASS-dev] Re: Profiler updates

[Michael Barton]

Hamish,

See below


On 2/19/07 3:17 AM, "Hamish" <hamish_nospam at yahoo.com> wrote:
> 
> Hamish wrote:
>>> Currently the profile line interpolates over areas of null value.
>>> It would be more correct if the line stopped and then restarted
>>> when the data resumed. e.g.:
>>> 
>>>   http://bambi.otago.ac.nz/hamish/grass/profile_nulls.png
> 
> this is still a problem.

I'm just happy it doesn't crash. But it should now be possible to see if
there is a way to get better output in such circumstances too.

> 
> 
>>> wish 1: prettify max value on x-axis:
>>> +               -text "[format %g $cumdist]" \
> 
> maybe we want to improve on that more? set to %.2f then pass that string
> through %g?  ie limit to 2 decimal places and strip off .00.  ??
> or %.1f?  %.0f?
> 

My concern is that we limit the decimal places where there needs to be many
(e.g., zooming in with locations in decimal degrees). Maybe I'm not
understanding the formatting codes.

>>> wish 2: add units to the axes.
>>> # x-axis: r.profile always return meters
>>> # y-axis get units (plural) from g.proj:
> 
> you are reporting the y units (from g.proj -p) on the x-axis. The
> x-axis is always meters because that's what libgis returns.

I don't think so. If I switch to a location in decimal degrees, the x-axis
label says "distance along transect (degrees)". G.proj is reporting the
horizontal units not the vertical ones.

The vertical units are determined by the nature of the map (elevation vs.
rock types for geology). This is why I decided not to put in y-axis units.

> 
> For the x-axis, perhaps dist/1000 to make km if distance is >2500m?
> (see crude but functional attached patch)

This might be a nice way to make the formatting easier to read.

> 
> 
>>> wish 3: write distance labels for ticks along the x-axis.
>>> I'm not sure how to guarantee that they won't overlap if too close
>>> together.
> 
> nice.

Thanks


Michael

__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton