[Thuban-list] classification of variable ratios, not only single variables

[Moritz Lennert]

Hello,

I'll just keep going until someone stops me ;-)

How difficult would it be to introduce the possibility of classifying a
map according to the ratio of two variables instead of one variable alone.
As an example: if I have a map whose data table contains population and
surface for each spatial entity, I have to go into the data file (outside
of thuban) and calculate the population density and then I can generate a
map of this density. It would be nice to have the possibility to indicate
two variables, one as nominator and one as denominator and then launch the
classification on this ratio.

Moritz