dove's and hawk's

[bluatigro]

there are bird's

they are dove or hawk

if to bird's try to eat

- if 2 hawk's

-- they fight and get damage and no food

- if 1 hawk and 1 dove

-- hawk eat's al food

- if 2 dove's

-- they share the food

error :

the sim shoot show a smal number of hawk's

and a great number of dove's

but it keeps it +- 50 : 50

[/p][p]'' bluatigro 2 nov 2018
'' hawk and dove
dim bird( 100 ) , e( 100 )
global hawk , dove
hawk = 1
dove = 2
for i = 0 to 100
 bird( i ) = irange( 1 , 2 )
 e( i ) = 10
next i
for j = 0 to 1000
 hawktel = 0
 dovetel = 0
 for i = 0 to 100
   dice = irange( 0 , 100 )
   if i <> dice then
     e( i ) = e( i ) + eat( bird( i ) , bird( dice ) )
     if e( i ) < 0 then
       bird( i ) = irange( 1 , 2 )
       e( i ) = 10
     end if
     if e( i ) > 20 then
       bird( dice ) = bird( i )
       e( dice ) = 10
     end if
   end if
   if bird( i ) = hawk then hawktel = hawktel + 1
   if bird( i ) = dove then dovetel = dovetel + 1
 next i
 print hawktel , dovetel
next j
end
function irange( low , high )
 irange = int( rnd(0) * ( high - low + 1 ) + low )
end function
function eat( a , b )
 if a = hawk then
   if b = hawk then
     eat = -6
   else
     eat = 2
   end if
 else
   if b = hawk then
     eat = 0
   else
     eat = 1
   end if
 end if
 eat = 0
end function
[/p][p]

[tenochtitlanuk]

Your function eat has a last line which makes eat always =0!

[B+]

Heck of a diet plan!

[bluatigro]

update :
i altered eat()
now i get good results


this is proof that coperation is better than competision


'' bluatigro 2 nov 2018
'' hawk and dove
global pop : pop = 1000
dim bird( pop ) , e( pop )
global hawk , dove
hawk = 1
dove = 2
for i = 0 to pop
 bird( i ) = irange( 1 , 2 )
 e( i ) = 10
next i
for j = 1 to 512
 hawktel = 0
 dovetel = 0
 for i = 0 to pop
   dice = irange( 0 , pop )
   if i <> dice then
     e( i ) = e( i ) + eat( bird( i ) , bird( dice ) )
     if e( i ) < 0 then
       bird( i ) = irange( 1 , 2 )
       e( i ) = 10
     end if
     if e( i ) > 20 then
       bird( dice ) = bird( i )
       e( dice ) = 10
     end if
   end if
   if bird( i ) = hawk then hawktel = hawktel + 1
   if bird( i ) = dove then dovetel = dovetel + 1
 next i
 q = log( j ) / log( 2 )
 if q = int( q ) then
   print j , hawktel , dovetel
 end if
next j
print "[ end sim . ]"
end
function irange( low , high )
 irange = int( rnd(0) * ( high - low + 1 ) + low )
end function
function eat( a , b )
 if a = hawk then
   if b = hawk then
     uit = -6
   else
     uit = 2
   end if
 else
   if b = hawk then
     uit = 0
   else
     uit = 1
   end if
 end if
 eat = uit
end function


[tenochtitlanuk]

I've always liked these predator/prey simulations. Here's my adapted version to give a graphic front end, making clear the way rises in one population cause drop in the other, but despite the random disturbances they self-level.

' bluatigro 2 nov 2018, modified
'' hawk and dove

nomainwin

WindowWidth  =1330
WindowHeight = 550

open "Predation" for graphics_nsb as #wg

#wg "trapclose quit"
#wg "size 2"

#wg "goto 10 500 ; down ; backcolor 50 100 160 ; boxfilled 1012 10"

for axis =0 to 500 step 100
   #wg "up ; goto 10 "; 500 -axis; " ; down ; goto 1010 "; 500 -axis
next axis

#wg "size 1"

dim bird( 100), e( 100)
global hawk, dove
hawk = 1: hawktelO =1
dove = 2: dovetelO =1

for i = 0 to 100
 bird( i ) = irange( 1 , 2 )
 e( i ) = 10
next i

for j = 0 to 1000
 hawktel = 0
 dovetel = 0

 for i = 0 to 100
   dice = irange( 0, 100)

   if i <> dice then
     e( i ) = e( i ) + eat( bird( i ) , bird( dice ) )

     if e( i ) < 0 then
       bird( i ) = irange( 1 , 2 )
       e( i ) = 10
     end if

     if e( i ) > 20 then
       bird( dice ) = bird( i )
       e( dice ) = 10
     end if

   end if

   if bird( i ) = hawk then hawktel = hawktel + 1
   if bird( i ) = dove then dovetel = dovetel + 1
 next i

 #wg "color red      ; line "; j +10; " "; 500 -4 *hawktelO; " "; j +10; " "; 500 -4 *hawktel
 #wg "color darkblue ; line "; j +10; " "; 500 -4 *dovetelO; " "; j +10; " "; 500 -4 *dovetel
 hawktelO =hawktel
 dovetelO =dovetel

 #wg "size 3 ; color 0 160 0 ; set "; 1040 +hawktel *4; " "; 500 -dovetel *4

 scan
next j

wait

#wg "getbmp scr 1 1 1330 550"
bmpsave "scr", "birds.bmp"

end

function irange( low , high )
 irange = int( rnd( 0) * ( high - low + 1 ) + low )
end function

function eat( a , b )
 if a = hawk then
   if b = hawk then eat = -6 else eat = 2
 else
   if b = hawk then eat = 0 else eat = 1
 end if
end function

end

sub quit h$
   close #wg
   end
end sub


Incidentally, it can get stuck with one species all dead....

[tsh73]

>>making clear the way rises in one population cause drop in the other
That's because in this model total population is fixed.

This is not have to be this way.

[tenochtitlanuk]

It's easy to model these unrealistically simplified cases, and you learn a lot from them. Just remember that putting in rubbish rules will give rubbish output ( GIGO)!
See my predator/prey stuff at population modelling and modelling human population pyramids

[B+]

So what is first step towards making the model more realistic and thus more useful to humanity and it's future on earth?

[bluatigro]

update :
try at grass , cow and lion world

error :
there shoot be cow's and lion's in this grass world



'' bluatigro 7 nov 2018
'' grass cow lion sim
global world
world = 1000
dim q( world ) ,  e( world )
global cow , lion , grass , empty , energie
cow = 1
lion = 2
grass = 3
energie = 24
for i = 0 to world
 q( i ) = grass
 if rnd(0) < .1 then
   q( i ) = cow
   e( i ) = energie
 end if
 if rnd(0) < .02 then
   q( i ) = lion
   e( i ) = energie
 end if
next i

for tel = 0 to 1000
 cowtel = 0
 liontel = 0
 grasstel = 0
 for i = 0 to world
   dice = int( rnd(0) * world )
   if i <> dice then
     select case q( i )
       case cow
         q( i ) = empty
         if q( dice ) <> lion then
           if q( dice ) = grass then
             e( dice ) = e( i ) + 3
           else
             e( dice ) = e( i ) - 1
           end if
           q( dice ) = cow
         end if
         if e( dice ) > energie * 2 then
           q( i ) = cow
           e( i ) = energie
           e( dice ) = energie
         else
           e( i ) = 0
         end if
       case lion
         q( i ) = empty
         if q( dice ) = cow then
           e( dice ) = e( i ) + 3
           q( dice ) = lion
         else
           e( dice ) = e( i ) - 1
           q( dice ) = lion
         end if
         if e( dice ) > energie * 2 then
           q( i ) = lion
           e( i ) = energie
           e( dice ) = energie
         else
           e( i ) = 0
         end if
         e( i ) = 0
       case grass
         if q( dice ) = empty then
           q( dice ) = grass
         end if
       case else ''empty
     end select
     if e( i ) < 0 then
       e( i ) = 0
       q( i ) = empty
     end if
   end if
   if q( i ) = cow then cowtel = cowtel + 1
   if q( i ) = lion then liontel = liontel + 1
   if q( i ) = grass then grasstel = grasstel + 1
 next i
 print tel , grasstel , cowtel , liontel
next tel
print "[ end sim ]"



[bluatigro]

update :
i got cow's in my world
error :
the lion's die quickly out

'' bluatigro 7 nov 2018
'' grass cow lion sim
global world
world = 1000
dim q( world ) ,  e( world )
global cow , lion , grass , empty , energie
cow = 1
lion = 2
grass = 3
energie = 10
for i = 0 to world
 q( i ) = grass
 if rnd(0) < .7 then
   q( i ) = cow
   e( i ) = energie
 end if
 if rnd(0) < .4 then
   q( i ) = lion
   e( i ) = energie
 end if
next i

for tel = 0 to 1000
 cowtel = 0
 liontel = 0
 grasstel = 0
 for i = 0 to world
   dice = int( rnd(0) * world )
   if i <> dice then
     select case q( i )
       case cow
         q( i ) = empty
         if q( dice ) <> lion then
           if q( dice ) = grass then
             e( dice ) = e( i ) + 3
           else
             e( dice ) = e( i ) - 1
           end if
           q( dice ) = cow
         end if
         if e( dice ) > energie * 2 then
           q( i ) = cow
           e( i ) = energie
           e( dice ) = energie
         else
           e( i ) = 0
         end if
       case lion
         q( i ) = empty
         if q( dice ) = cow then
           e( dice ) = e( i ) + 10
           q( dice ) = lion
         else
           e( dice ) = e( i ) - 1
           q( dice ) = lion
         end if
         if e( dice ) > energie * 2 then
           q( i ) = lion
           e( i ) = energie
           e( dice ) = energie
         else
           e( i ) = 0
         end if
         e( i ) = 0
       case grass
         if q( dice ) = empty then
           q( dice ) = grass
         end if
       case else ''empty
     end select
     if e( i ) < 0 then
       e( i ) = 0
       q( i ) = empty
     end if
   end if
   if q( i ) = cow then cowtel = cowtel + 1
   if q( i ) = lion then liontel = liontel + 1
   if q( i ) = grass then grasstel = grasstel + 1
 next i
 if tel mod 100 = 0 then
   print tel , grasstel , cowtel , liontel
 end if
next tel
print "[ end sim ]"



[tenochtitlanuk]

Replying to B+'s comment.
All simulations about world ecology are almost by definition limited- we don't know all the variables, nor how they interact.
At a simple level, the interactions MUST be more familiar in future if the Earth is to have a future.
This is where these simulations can have a great educational value for young people.
( Of course at an international level the simulations will be at the limits of what we know and can compute. We do now know much more about the important interactions. Business 'games' help develop business talent- even tho' economics is not the precise science its practioners think it is...Think too how much weather forecasts have improved in our lifetimes...)

I found the population program on my website a great introduction for my students to the delayed impact of changes in disease, food supply or war- and on future taxation needs for aging retirees. Everyone should understand what a population pyramid is, and how it should influence decisions on how to develop our own countries and help the underdeveloped. Have small student groups implement changes, and see if they can generate a steady population- or a controlled reduction. Throw in random war or disease, an oil price hike, or a revolt of pensioners whose pensions are no longer affordable. . Lively debate ensued, as they say, on the need for say compulsory euthanasia at 60; or compulsory birth control limits; or 'culling' male children since women are generally more peaceful and able to cooperate.. Let's have a debate, as they say!!!

[bluatigro]

update :
this is also known as fox and rabbit

try to get a 'stable' population
[ that is whit cycly ]

or did i make a error ?


'' bluatigro 14 nov 2018
'' fish and shark
input "fish : " ; fish
input "shark : " ; shark
input "fish get child : " ; a
input "shark eat fish : " ; b
input "shark get child : " ; c
input "shark die : " ; d
tel = 0
while shark > 0 and tel < 1000
 print shark , fish
 dfish = fish * a - shark * b
 dshark = fish * c - shark * d
 fish = fish + dfish
 shark = shark + dshark
 tel = tel + 1
wend
print "[ end sim ]"



[B+]

I have been sitting here meditating on how to get a decent model going. It started with an IF THEN question:

IF all fish eat are smaller fish THEN what do the smallest fish eat?

There is no smallest fish? ;-)) (But there is something called land which includes elements mostly recycled and energy mostly from the sun.)

Then a couple of insights:
1) The whole chain is limited to the amount of the smallest fish.
2) The higher up the chain the significantly smaller the balance of that species population must be. Each higher up number has to exist between the feast or famine numbers of next lower level.
3) Omnivores complicate this whole thing.
4) Bacteria are an extremely important part of cycle for plants to carry on.

[tsh73]

this is also known as fox and rabbit
...
or did i make a error ?


Wikipedia
en.wikipedia.org/wiki/Lotka%E2%80%93Volterra_equations
has "fish*shark" term in both equations.

EDIT

---

Gotta love that!

"atto-fox problem"

_{, an atto-fox being a notional 10^−18 of a fox}

These graphs illustrate a serious potential problem with this as a biological model: For this specific choice of parameters, in each cycle, the baboon population is reduced to extremely low numbers, yet recovers (while the cheetah population remains sizeable at the lowest baboon density). In real-life situations, however, chance fluctuations of the discrete numbers of individuals, as well as the family structure and life-cycle of baboons, might cause the baboons to actually go extinct, and, by consequence, the cheetahs as well. This modelling problem has been called the "atto-fox problem", an atto-fox being a notional 10^−18 of a fox

[tsh73]

John,
just tried your "population pyramid" program.
It balks at loading "Malthus.txt"
my guess that it's just help text in big right textbox
- works fine if commented out
(or "autoexec" imply one could program some events to mimic button presses?)

Reading program is a treat.

So it is totally deterministic, no RND?

Rather dark humor. Me likes.
(this doesn't prevent me being afraid, but playing "dictator" I got used to starving electronic populace).