Getting a property for each turtle

[Iuval]

This should be trivial and quite common! But apparently not. I have defined “effort” thus:

turtles-own [effort
...]
to setup-turtles
   ask turtles [   
    set effort random-float 5 
..,]
end

and now I want each turtle to do some stuff within the radius of its own “effort”

to move-turtles
  ask turtles [
    set rad [effort] of myself
    ask patches in-radius rad[
      set yum max-one-of patches [presource]
    ]
...
end

“yum” is defined previously as

patches-own [
  yum
...
]

I get the following error:

There is no agent for MYSELF to refer to.

error while turtle 5 running MYSELF

called by procedure MOVE-TURTLES

called by procedure GO

called by Button ‘go’

Suggestions?

[jzkelter]

This is one of the more confusing parts of NetLogo. You don’t need to use myself here you can just do

to move-turtles
  ask turtles [
    set rad effort
    ask patches in-radius rad [ ; (of course you could just use `in-radius effort` here)
      set yum max-one-of patches [presource]
    ]
...
end

myself is used to refer to the asker agent when agents ask other agents to do things. For example if you had two types of turtles called sheep and goats

ask sheep [
    ask one-of goats [
        set xcor [effort] of myself
    ]
]

That would have each sheep ask one goat to set its xcor to the effort value of the sheep that asked it to do that.

[Iuval]

That is the FIRST thing I tried, and got the error (in the statement:set dxx [pxcor] of yum - xcor):

OF expected input to be a turtle agentset or patch agentset or turtle or patch but got the number 0 instead.
error while turtle 6 running OF
called by procedure MOVE-TURTLES
called by procedure GO
called by Button ‘go’

[Iuval]

Thanks. I changed some other things, and it seems to work now. I wll soon post it to the common repository of models.

[jzkelter]

@Iuval

That is the FIRST thing I tried, and got the error (in the statement:set dxx [pxcor] of yum - xcor):

OF expected input to be a turtle agentset or patch agentset or turtle or patch but got the number 0 instead.
error while turtle 6 running OF
called by procedure MOVE-TURTLES
called by procedure GO
called by Button ‘go’

That error implies that yum was a variable with the value of 0 rather than a patch or turtle.

[Iuval]

I had to initialize it: set yum self in setup-patches.

Can you please tell me why my turtles jump more than is possible with the variable effort (currently set effort random-float 3 in setup-turtles)?
Currently I have:

to move-turtles
  ask turtles [
    ask patches in-radius effort[
      set yum max-one-of patches [presource] ;;the patch with the largest resource
    ]
    set dxx [pxcor] of yum   - xcor
    set dyy [pycor] of yum - ycor
    ifelse  dxx = 0 AND dyy = 0 ;; stay in place if patch is already the highest resource
     [
      set dist 0
      ]
     [set heading atan dxx dyy
      set dist sqrt ( dxx * dxx + dyy * dyy) ;; 
      jump dist] ;;go to patch with largest resource

...]

end

[jzkelter]

Rather than debugging this, I’ll give you a way easier way to do this in a NetLogo-y way:

ask turtles [
    move-to max-one-of patches in-radius effort [presource]
]

That should do what you want (move to the patch with the largest resource within the radius effort including if that patch is the one the turtle is currently on).