[GRASS-dev] Scale display in GRASS Monitor

[Daniel Calvelo]

How about having a global conversion factor that can be calibrated,
e.g. as an environment variable.

Give the user the option to manually calibrate that: show him a bar or
set of bars, ask him to measure it/them using a ruler and report the
results. That would be neat at graphical startup screens. We can even
have our own (reliable) measures to test against absurd values.

Just an idea. It's rather odd that no GIS implements this kind of
artisanal method...

Daniel.

On 9/23/06, Glynn Clements <glynn at gclements.plus.com> wrote:
>
> Markus Neteler wrote:
>
> > > It's a lot more robust to just use a scale bar like d.barscale.
> >
> > Could the method of d.barscale somehow be used?
>
> What method?
>
> d.barscale just draws a bar with a given length in map coordinates. It
> neither knows nor cares how large the bar will be (physically) on the
> monitor.
>
> d.barscale only needs to be able to transform map coordinates to
> pixels, which we do whenever we draw a map. It's converting pixels to
> physical dimensions which is problematic.
>
> --
> Glynn Clements <glynn at gclements.plus.com>
>
> _______________________________________________
> grass-dev mailing list
> grass-dev at grass.itc.it
> http://grass.itc.it/mailman/listinfo/grass-dev
>


-- 
-- Daniel Calvelo Aros