I'm trying to create a model where turtles walk randomly (but with a tendency for forward movement) until they land on a yellow coloured patch which represents a baited object.
When a turtle lands on one of the yellow patches, I'd like it to stop on that patch and stay there for 15 ticks whilst it 'investigates' the bait.
After 15 ticks have elapsed I want the turtles to continue moving as usual until they encounter another yellow patch.
I've attempted to modify parts of this parked card model in the netlogo modelling commons but couldn't really make sense of it (I'm new to netlogo) http://modelingcommons.org/browse/one_model/3205#model_tabs_browse_procedures
I've also tried implementing a count-down timer as described in this thread How can one create a countdown timer in NetLogo?
However I receive a runtime error 'Only the observer can ASK the set of all turtles' when I try to run the simulation. Can anyone tell me where I'm going wrong? Probably several places! Thanks.
Here's the code that's causing the runtime error:
turtles-own [count-down]
to setup
clear-all
ask patches with [count neighbors != 8]
[set pcolor blue]
create-turtles 20
ask turtles
[setxy random-xcor random-ycor
pen-down]
ask n-of 20 patches
[ set pcolor yellow ]
reset-ticks
end
to go
move-turtles
tick
if ticks >= 720 [stop]
end
to move-turtles
ask turtles
[ ifelse pcolor != yellow
[continue]
[stay]
]
end
to continue
ask turtles
[rt -90 + random 181]
ask turtles
[ifelse [pcolor] of patch-ahead 1 = blue [ lt random-float 360 ]
[fd 1]
]
end
to stay
ask turtles
[
setup-timer
decrement-timer
if timer-expired? [continue]
]
end
to setup-timer
set count-down 15
end
to decrement-timer
set count-down count-down - 1
end
to-report timer-expired?
report ( count-down <= 0 )
end