So for part of my model, I want my turtles (in this case, deer, specifically juvenile female deer) to "disperse" according to certain criteria. Here is what I have so far:
to move-dispersing-femjuvs
ask femjuvs [
let natal-range patches in-radius 5
let density (count femadults-on natal-range + count maleadults-on natal-
range + count femjuvs-on natal-range + count malejuvs-on natal-range +
count infants-on natal-range)
let chance-disperse 1 / (1 + exp(2.051 - (0.002605 * density)))
if (random-float 1.001 < chance-disperse) [
let mean-distance (18.703 + (0.02533 * density))
I believe this will give me the proportion of the female juveniles that will disperse, as well as the mean dispersal distance, taken from literature (I realize the if statement is incomplete, this is where I'm stuck). My question is, how do I get the "femjuvs" who are dispersing to actually move? They would move until they reach an unoccupied patch in a radius that does not overlap the "natal range". Ideally, I would want all of the distances of the femjuvs who do disperse to have a mean of "mean-distance". I have "dispersal-distance" as a "femjuvs-own" variable, but I haven't set it to any value.
Any help with any part of this problem is appreciated. Thank you!
Possibly use: "setxy" or "forward"
setxy
If the aim is to update a deer position over time, calculating its coordinates, setxy might be a good option. This isn't so much moving as it is adjusting its coordinates.
ask femjuvs [ setxy <xcor> <ycor> ] ; example
ask femjuvs [ let x-coordinate <some-long-computation>
let y-coordinate <some-longer-computation>
setxy x-coordinate y-coordinate ]
forward
To move a deer, there is a function called "forward" that can be invoked by femjuvs (turtle/breed context):
ask femjuvs [ forward <number> ]
It would move femjuvs n spaces in the direction it is facing, where is the number specified.
Possible additions: (* - relevant functions)
to move-dispersing-femjuvs
ask femjuvs [
let natal-range patches in-radius 5
let density (count femadults-on ...) ; shortened for space
* forward 1 ; move forward one
]
...
end
Also, if dispersing from a given point or coordinate is necessary, having the deer face the point and turn it 180 degrees could work.
ask femjuvs [ face <random-point> ; or facexy <xcor> <ycor>
left 180 ] ; turn the opposite direction
ask femjuvs [ forward 1 ] ; disperse
One thing to note is that if the direction is not set by the developer, NetLogo will store a direction beforehand, which may or may not be helpful.
More details in : https://ccl.northwestern.edu/netlogo/docs/dictionary.html
Related
I am new to Netlogo and learning a model is about animals moving around to eat grass based on the grazing model from NetLogo. The moving behavior is based on the biomass's richness, so it is not just impacting at right angles.
Given the conditions, I don't know how to add a monitor in my model that calculates the total distance a turtle moved by traveling each pixel.
Move specifically, I wonder if there is a way to calculate the total length of the pen-marked lines. (Show in the picture)
enter image description here
The basic setting of move is
to move-turtles
uphill-biomass
forward 1
set distance-traveled (distance-traveled + 1)
if not can-move? 1 [ rt random 150 ]
end
to uphill-biomass
let biomass-ahead biomass-scent-at-angle 0
let biomass-right biomass-scent-at-angle 35
let biomass-left biomass-scent-at-angle -35
if (biomass-right = biomass-ahead) and (biomass-left = biomass-ahead) [ wiggle ]
if (biomass-right > biomass-ahead) or (biomass-left > biomass-ahead)
[ ifelse biomass-right > biomass-left
[ rt 35 ]
[ lt 35 ] ]
end
Thank you very much for any helps!
You need to use some turtle variables with the turtles-own primitive and do the distance calculation by hand.
The easiest way to do such a calculation is to save the coordinates between a turtle's previous coordinates with turtle variables and then use the distancexy primitive (link for dictionary entry: https://ccl.northwestern.edu/netlogo/docs/dictionary.html#distancexy)
Here's a simple implementation:
turtles-own [last-x last-y distance-traveled]
move-turtle
uphill-biomass
set last-x xcor
set last-y ycor
forward 1
set distance-traveled (distance-traveled + (distancexy last-x last-y))
if not can-move? 1 [ rt random 150 ]
end
I hope this answers your question.
I wish to find out whether in a given turtle's heading there is another agent present upto a given distance.
Here the Distance is "D".
Note:
Any agent present before D in the given direction should be also considered.
Even the direction doesn't coincide with the other's agent centre but just touches it ,even then that agent should be considered.
Problem:
No turtle-ahead procedure available. Combination of patch-ahead and turtles-on not applicable due to patch-size>> turtle-size.
Possible approach:
1.Represent the turtle's heading by the equation of a line.
to-report calculate-line[x y angle]
let m tan angle
let A m
let B -1
let C (- m * x + y)
report (list A B C)
end
to-report heading-to-angle [ h ]
report (90 - h) mod 360
end
let line-equ calculate-line (xcor) (ycor) (heading-to-angle heading)
2.Calculate the perpendicular distance from other turtles here, Check if there are within a range that the size of other turtles.
to-report value[A X1 Y1];;A is list of coefficents of line, x1 and y1 are coordinates of red turtle
if-else(abs((item 0 A * X1 + item 1 A * Y1 + item 2 A) / (sqrt((item 0 A ^ 2) + (item 1 A ^ 2) ))) < [size] of wall )
[ report "true"][report "false"]
end
3.To check if the red turtle is within D. One could obtain a line perpendicular to black one and compute the red turtle distance from it to check if it is less than or equal to D. But then that adds more complication.(Though one can simplify rotate the turtle by 90 left or right and get the line equation.)
This is what I meant by my comment. Run this code (as its own model). What it does is turn all the turtles on a few 'ahead' patches a different colour. I know this is not what you are trying to do, but the agentset candidates is a relatively small number of turtles. These are the only ones that you have to check whether they are on the correct path. So instead of turning them a different colour you could check the direction that they are from your initial turtle.
to setup
clear-all
set-patch-size 25
resize-world -10 10 -10 10
create-turtles 1000
[ setxy random-xcor random-ycor
set color yellow
set size 0.4
]
ask one-of turtles
[ set color red
set size 1
check-from-me 5
]
end
to check-from-me [howfar]
let counter 0
let candidates turtles-here
while [counter < howfar]
[ set counter counter + 1
set candidates (turtle-set candidates turtles-on patch-ahead counter)
]
ask candidates [set color red]
end
to-report check-wall
let return false
hatch 1[
set color black
set size ([size] of one-of walls) / 2
show (2.5 * ([size] of myself))
while [distance myself < (2.5 * ([size] of myself))]
[
fd ([size] of one-of walls) / 64
if any? walls in-radius size
[
set return true
]
show distance myself
]
]
report return
end
The above works. But still is approx. I am looking for better solution with probably less maths as one elucidated in the question.
Is it possible to create random shapes (see below for example) of a given area in NetLogo?
A first stab at Seth's suggestion #1. It creates a neat visual too!
patches-own [ height ]
to blobbify
clear-all
repeat (ceiling 2 * (ln (world-height * world-width))) [
ask patch (round (random (world-width / 2)) - world-width / 4)
(round (random (world-height / 2)) - world-height / 4)
[ set height world-width * world-height ] ]
while [ count patches with [ height > 1 ] < (world-width * world-height / 4)]
[ diffuse height 1
ask patches with [ height > 0 ] [ set pcolor height ]
]
ask patches with [ height > 1 ] [ set pcolor white ]
end
I found a really simple approach that produces pretty nice results.
Create a turtle. The turtle performs a random walk. After each step, they set the uncolored patch closest to them to the desired color. The turtle does this a number of times equal to the desired area.
Here's the code:
to make-blob [ area ]
let blob-maker nobody
crt 1 [ set blob-maker self ]
repeat area [
ask blob-maker [
ask min-one-of patches with [ pcolor = black ] [ distance myself ] [ set pcolor blue ]
rt random 360
fd 1
]
]
ask blob-maker [ die ]
end
This naturally produces nicely curved blobs.
Making the turtle's step size smaller makes the blob more circle-y. Making it bigger results in thinner, more sporadic blobs (though you run the risk of getting disconnected patches).
Edit:
I noticed that my answer runs quite slowly when you have a gigantic number of patches. Here's a much faster version:
to make-blob [ area x y ]
let blob-maker nobody
crt 1 [ set blob-maker self setxy x y ]
let border patch-set [ patch-here ] of blob-maker
repeat area [
ask blob-maker [
ask min-one-of border [ distance myself ] [
set pcolor green
set border (patch-set border neighbors4) with [ pcolor = black ]
]
rt random 360
fd .8
]
]
ask blob-maker [ die ]
end
Generating random blobs is a hard problem with no obvious solution. Fixing the area of the blob makes it even harder.
You'll need to pick an approach, then try to figure out how to express that approach in NetLogo code.
As for what approach to pick, I imagine there's literature on this if you search. But just off the top of my head, I have three ideas:
Scatter random points around the world, use diffuse to make a smooth landscape around these peaks. (See the Diffusion Graphics model, in the Art section of NetLogo's Models Library, for code for this; you'll want to turn world wrapping off, though.) Then select only those patches where the "elevation" exceeds some threshold. To get the desired area, vary the threshold until the target is reached.
Draw a curve around the center point using polar coordinates, where theta goes from 0 to 360 and 4 varies randomly. You'll need a way to get smooth random variation in the radius, perhaps by generating random numbers and then applying a smoothing function to them. In order to force the blob to have the desired area, first generate the whole curve, then scale it as needed. You'll need some trick to avoid a discontinuity where theta = 0, perhaps by using a smoothing function that wraps.
Generate a random polygon by scattering points around the world, then discarding some or all points in the middle. (You could take the convex hull, but then you'll always get a convex shape, which might not be "blobby" enough for you. So you might want to something like like generating n random points and then keeping the m points that are farthest from the center, without regard to convexity.) Once you've got the random polygon, apply some smoothing function to turn it into a curvy blob. Then scale the whole thing as necessary to get the desired area.
I was wondering if anyone has a good idea to filter turtles who have the caller turtle in their vision and in their cone of vision with the least computational cost?
Now I am using something like this:
Member? Caller-Agent agents in-cone 5 100
or just who are agents who can see me?
I was wondering if anyone knows how can I check if heading of other agents in some radius X is toward the caller agent ?
So , this is the way I did it:
I used abs( towards myself - heading) < 50
I thought it might include cone with angle of 100 since it uses absolute value.
This is just a test program to see if it works:
ask turtles[set label "" set color green]
ask turtle 7 [
set color red
set label "Caller"
ask other (turtles with [distance myself <= 3 and abs( towards myself - heading) < 50 ])
[
set color yellow
]
ask other turtles [
set label (Member? turtle 7 Other turtles in-cone 3 100)
]
]
and this one cone 80 and abs( towards myself - heading) < 40 :
There is a problem with this approach:
if an agent is as same location of the caller then I will get the error that there is no heading defined to same point or something like that!
Error is : No heading is defined from a point (7,7) to that same point. error while turtle 28 running TOWARDS
Update:
[(distance myself <= 3 and distance myself > 0 and abs( subtract-headings towards myself heading ) < 60) or distance myself = 0 ]
I've made a model that aranges factions (turtles in different colours) in a circle.
At the moment they arrange randomly, was wondering if someone could help me arrange them so, for example, red occupies the first 90 degrees, blue the next 90 degrees, etc (on setup).
Here's my code...
ask patch 0 0
[ ask patches in-radius ( max-pxcor * .9) with [ random-float 100 < density ]
[ sprout 1
[ set breed cons
set shape "circle"
set faction random factions
set heading random 360
set size 1
]
]
]
.. guessing I will have to do 360 / fractions, but not sure how to phrase it, if someone could help me out that'd be great. Thanks!
The NetLogo primitive that's the closest to what you want to do is in-cone, which reports the set of turtles that are in the "cone of vision" of another turtle. But your "pie slices" should just be relative to patch 0 0, not to another turtle! No problem: just make a temporary turtle at patch 0 0, use it to get turtles in-cone with the appropriate angle, and kill your temporary turtle.
The following procedure can be used "as is" with your code (just call it from your setup procedure after creating your turtles exactly as you were doing before):
to assign-factions
let angle 360 / factions
foreach n-values factions [?] [
ask patch 0 0 [
sprout 1 [
set heading ? * angle
ask turtles in-cone max-pxcor angle [ set faction ? + 1 ]
die
]
]
]
end
The code is pretty straightforward, except for maybe the more obscure n-values. You could replace it with a while loop if you prefer, but it's really just counting from 0 to factions.
Here is what you'd get with 5 factions: