Netlogo - Filling neighboring patches with specific colored turtles until full

Question

I'm trying to ask white turtles to create yellow turtles to one of the 8 empty neighboring spaces. If there is no free space the turtle should produce nothing. Note: white turtles stay white and produce yellow turtles which are able to reproduce themselves as well as other yellow turtles. In summary, at the end I would like to fill up the black spaces with yellow turtles.

breed [ cells cell ]
cells-own [ n ]

to setup
  clear-all
  set-default-shape cells "square"
  ask patches [ if pycor = min-pycor [sprout-cells 1]]
  ask cells [ ifelse random 10 < 2 [set color white] [set color yellow]]

Thanks for the reply.

I'll explain what I'm trying to do:

1. The white squares represent "stem cells" which have the ability to reproduce themselves and produce another type of cell (e.g. TA cell), so that, initially each white cell will produce another cell above it or at one of its above corners.
2. In the second step, each TA cell produces other cells randomly in any empty space around it.
3. Third, stem cells (white squares) repeat step 1 and at the same time TA cells fill in one of the empty spaces around them. The cells (both stem cells and TA cells) stop producing new cells once they have no empty space around them (when the 8 neighbors are already filled in).
4. At the final stage all of the black space should be filled in with TA cells. The yellow squares at the last row basically do nothing.

Thanks again for your help.

  reset-ticks
end

to go
  ask cells
    [ set n count neighbors with [pcolor = yellow] ]
  ask cells
    [ if n >= 1
      [ set color yellow] ]
  tick
  ;ask cells 
  ;[if ticks = 10
    ;[set color yellow]]
end

Answer 1

What exactly you are trying to do is not entirely clear to me. I am going to go with a likely interpretation, but whether or not my interpretation is correct, you should try to clarify your question.

Trying to understand your code, it seems to me like there is a bit of confusion between patches and turtles. In your go procedure, you ask cells to turn yellow if they have a yellow neighbor. I think that what you want is for a yellow square to appear on patches that are neighbors of yellow squares. The empty patches you are trying to fill don't have any cells on them yet, so ask cells to turn yellow will not help you here.

If you really want to stick with cell agents, keeping your current setup procedure, you could do something like:

to go
  ask patches with [not any? turtles-here] [
    if any? neighbors with [any? turtles-here] [
      sprout-cells 1 [
        set color yellow
      ]
    ]
  ]
end

(If you want your cells to grow from the bottom up only, you should turn off wrapping in the view settings by right clicking on the view and choosing Edit...)

Now, a completely different approach, that may be simpler if all you want is some kind of cellular automaton, would be to ditch agents and work only with patches. That would give you something like:

to setup
  clear-all
  ask patches [
    if pycor = min-pycor [
      ifelse random 10 < 2 
        [set pcolor white]
        [set pcolor yellow]  
    ]
  ]
  reset-ticks
end

to go
  ask patches with [pcolor = black] [
    if any? neighbors with [pcolor = yellow or pcolor = white] [
      set pcolor yellow
    ]
  ]
  tick
end

Both approaches are valid. The first one is a bit more visually pleasing. The second one is slightly simpler because you don't need turtles at all. It depends on what you ultimately want to do.