Hamish wrote:
Luigi Ponti wrote:
[...]
However, when you have a continuously varying color bar in the map,
you will have label numbers next to the bar and you will try to
associate the bar color next to the label value with a color in the
map. The argument Borland & Taylor (2007) make is that if each label
of the color bar is located between two constant color bands in the
bar, you will have that value easily located in the map along the
boundary between the two contiguous areas of constant color. What do
you think about this?
So they argue that (filled) contour lines are better than continuous
rainbow legend. Well, why not draw contour lines over the top of a
continuous rainbow then? It is a false dichotomy, as you can do both
together. My feeling is that there is more room for danger with
contour lines than with the reader squinting to see what orangish-
yellow means. Contour lines are dangerous because they state loudly
where a transition is, regardless of if the data has that confidence or
not. It is like the difference between politicial speak and scientist
speak in a way, one gives black and white options, the other gives some
probability that a theory is correct.
OK -- I got the point and that's good because I don't have to change the
way I am doing things. Plus you provided good arguments to support it.
I have no bias given my very limited experience on the matter -- just
trying to make an informed decision. Thanks again for discussing this
and sorry if this is way off topic for the list (please advice).
I veer way offtopic as well, and again it reminds me about the next book
I need to borrow from the library (www.edwardtufte.com).
Yes: it's highly cited by both supporters and enemies of constant color
bands.
To claw back on topic I will mention that you can have a rainbow
colorscale with crossing band lines in ps.map: give the "tickbar"
instruction to the colortable command. (then create and overlay contours
at those levels)
That's something that can turn useful, thanks!
[...]
The statistical equivalent is to slowly vary the number
bins in a histogram while the peaks seemingly double and halve.
Yes, you lose information that way.
And worse, it is very easy to do so without noticing that you've done it.
Thank you for a very interesting thread -- it's nice to veer off-topic
every now and then.
Luigi
_______________________________________________
grass-user mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/grass-user
