[Qgis-developer] new symbology terminology

[Martin Dobias]

Hi Carson

On Mon, May 31, 2010 at 1:39 PM, Carson Farmer <carson.farmer at gmail.com> wrote:
> It has just occurred to me that the renderer types may be mislabeled
> in the new symbology dialog. It appears as though the Categorized
> renderer is actually set up for a continuous range of values, and the
> Graduated renderer is actually set up for classified ranges of values
> (i.e. requires the specification of the number of classes etc.). In
> fact, these two renderer types should be reversed. Obviously,
> categorization implies that objects are grouped into categories (or
> classes), whereas graduated symbology should really refer to a
> continuous colour variation, where each (numeric) value should be
> coloured according to its relationship with all other values in the
> field.
> Any thoughts by cartographers more experience than myself?

The categorized renderer is intended to be a renderer for discrete
values - categories - where the values do not refer to quantities.
Categorized symbol renderer has basically the same semantics the
Unique symbol renderer from old symbology. I'm not an experienced
cartographer and I've started to use the 'Categorized' name, because
I've found it more intuitive than 'Unique symbol' renderer - but I'm
not a native speaker and I can be wrong.

However, what leads you to think that categorized renderer is set up
for continuous ranges of values? Is it the possibility to apply
graduated color ramps?

Bye
Martin