Moritz wrote:
What is still missing right now is an easy way to display a
combination of color-classified and proportionately sized
symbols. It is possible to declare an arbitrary numeric
column as z-height and use that with zcolor, but I don't
think this is very straightforward and even though ISTR you
don't see the need for that, cartographic theory (at least
for thematic maps) still calls for reduced numbers of
classes.
The debate rages on whether class-splitting is a good idea or not.
<2c> In my personal opinion it is open to huge misleading abuse both
intentional and unintentional, and so I try to avoid it. Probably
even more so than the potential to abuse statistics because it also
plays tricks on your visual perceptions. For raster maps the best
compromise I know is to include continuous color maps with contour
lines over the top. For vector maps I don't know of a good compromise,
or even if one is possible. </2c>
However, if we go this way, I would need to add a flag to
d.vect which allows sorting symbols with the largest in the
back. This is absolutely necessary for readability. However,
this implies a fundamental change in the d.vect code,
As this is just the beginning, I would prefer a new module for that
along the lines of d.vect.chart.
why not simplify the name to just "d.thematic"?
regards,
Hamish
ps- see also v.colors and the new extra/ring symbol