Netlogo - selecting all turtles at a given distance from a special agent - netlogo

Question

I have to select and compute the nearest turtle from a fixed point, however i want the distance to be changeable, in the sense that i have a slider and i want to select the nearest turtle with that
given distance from that point.
I've tried many solution, also with the in-radius function, but it does not produce the desired output.
Can anyone help me? thanks in advance.

Answer 1

Enrico, I don't have enough reputation points to comment so I'll post this as an answer. Your question was two weeks ago and you may no longer need an answer.
If the discussion below correctly describes your problem, as well as the generic logic involved in it, you should have enough to be able to write the basic NetLogo model, or to get the basic control structures written and focus on the specific point where you can't figure out the NetLogo syntax to implement the desired functionality. Or perhaps you have code already in place and we just haven't seen it here.
At that point, the wonderful StackOverflow members should be able to help you answer specific questions in a shared context and understanding of what you're trying to do, what code you are using, and what happens when you try to run the model.
Is the following a correct restatement of your problem?
The Situation
The situation is a stage in a theater with multiple rows of seats. People come in one at a time and are always seated in the row nearest the stage that still has at least one empty seat. When that row is full, seating begins in the next row further away from the stage. When all rows are filled, the simulation stops. Within a row that has more than one empty seat, a seat is chosen that is maximizes some measure of collective distance from other seated people, including possibly people in other rows.
Question -- is the theater rectangular with linear rows of seats, or circular with concentric circular rows of seats around the stage?
Design Considerations
The collective-distance-metric calculation can be put into a separate routine and doesn't affect the rest of a basic NetLogo model setup.
Some possible metrics might be:
1) maximize the distance to the nearest seated person in the same row
2) maximize the distance to the nearest seated person in the entire theater
3) maximize the sum of distances to everyone seated in the same row
4) maximize the sum of distances to everyone seated in the entire theater
5) maximize the square root of the sum of squares of distance to everyone
* in the theater who smokes cigars.
Regardless of choice of metric, we will logically always do the same thing:
Pick initial seating arrangement and possibly initial seated persons
Pick the row to work on next
Loop
Pick which row to work on next, or exit if all rows are full
For each empty seat in that row
Find the agent-set of filled-seats that are relevant to the calculation
( say, filled-seats in the same row as the empty seat )
For that agent-set, compute the collective-distance-metric
Then pick the empty seat which generated the maximum collective-distance-metric
Sit there
update global statistics as desired
display statistics as desired
end-loop
NetLogo Implementation
Do what you can and come back with it here.
You might want to make people and seats two different breeds of turtles. You can layout all the seats in "setup" and then add people as you go.
Seats could own variables "row" and "occupied?" It's easy to layout circular rings of turtles using the "layout-circle" function. Maybe make unoccupied seats green circles of size 2, and change them to red when they become occupied.