Am 01.06.2022 um 07:55 schrieb John Paravantis:
I am talking about adding the values of a qualitative variable, e.g. country codes, as labels.

As an example from my megacity research, imagine a scatter plot of carbon footprint (y-axis) vs city population (x-axis). In such a plot, it would be very useful if the data points were labeled with the megacity name.
OK, so it's the (string) values of another variable. In gretl terms, these are called "observation markers" or labels, if I'm not totally missing something. As I wrote before, please see ch. 6 in the guide, subsection "Displaying data labels", which deals explicitly with scatter plots.

So I am suggesting that two separate improvements be considered for gretl:

(1) Add the capability of handling qualitative (i.e. text) variables, something that is sorely missing right now.
No it's not. I also wrote before that string-valued series may be what you want, and there's an entire chapter in the user guide (unless you are using a severely outdated gretl version).

(2) Add the capability of adding a qualitative variable as labels of the points of a scatter plot.

See above. To start with, data menu / add observation labels. And/or the "markers" command, which also allows you to use a strings array as your source object. I admit it may be a bit confusing to keep "variable labels" and "observation labels" (== markers) apart. (Internal note: maybe we should avoid the term observation labels in the documentation and replace it with obs markers to match the command name.)

cheers

sven