Simulate predator prey system using loops

I've written a code to simulate a predator-prey system in MATLAB (code below). I want to simulate the movements of each animal, but I don't know how to turn the output of a loop into a simulation. I'm quite new to MATLAB so some help would be appreciated. To clear things up: I've put each animal in a structure and put those in two maps: one for preys and one for predators.

% VARIABELEN
numDays = 50;
probbrirthPrey = 0.06;
probbirthPred = 0.04;
birthagePrey = 10; 
birthagePred = 10; 
axis = 10;
W = 0:1:axis;
rpred = 2;
rprey = 1.5;
preyid = 0;
predid = 0;

% MAPPEN MET INITIËLE DIEREN
predMap = containers.Map('KeyType', 'int64', 'ValueType', 'any');
pred = struct('x', rand * axis, 'y', rand * axis, 'age', 25, 'honger', 0);
predid = predid + 1;
predMap(predid) = pred;

preyMap = containers.Map('KeyType', 'int64', 'ValueType', 'any');
prey = struct('x', rand * axis, 'y', rand * axis, 'age', 15);
preyid = preyid + 1;
preyMap(preyid) = prey;
prey = struct('x', rand * axis, 'y', rand * axis, 'age', 20);
preyid = preyid + 1;
preyMap(preyid) = prey;

fields = {'x', 'y', 'age'};

% DAGEN
for t = 1:numDays
    disp(['---> DAG ', num2str(t),':']);
        
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% PROOIDIEREN (PREYS)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    
    disp('Prooidieren:');
    for p = keys(preyMap)
        thep = p{1};
        fprintf('  Prooidier %d\n',thep);
        newPrey = preyMap(thep);
        fprintf('    Coördinaten: (%.2f, %.2f)', newPrey.x, newPrey.y)                       
% COÖRDINATEN
        d = rand * rprey;
        rad = rand * 2 * pi;
        
        newpreyx = newPrey.x + cos(rad) * d;
        newpreyy = newPrey.y + sin(rad) * d;
        
        while newpreyx<0 || newpreyx>axis || newpreyy<0 || newpreyy>axis
            d = rand * rprey;
            rad = rand * 2 * pi;
            newpreyx = newPrey.x + cos(rad) * d;       
            newpreyy = newPrey.y + sin(rad) * d;
        end
                     
        newPrey.x = newpreyx;
        newPrey.y = newpreyy;
                     
% LEEFTIJD
        newPrey.age = newPrey.age + 1;

% WEERGAVE
        Plaats = sprintf('    Beweegt naar: (%.2f, %.2f)', newPrey.x, newPrey.y);
        disp(Plaats)        
        Leeftijd = sprintf('    Leeftijd: %d', newPrey.age);
        disp(Leeftijd) 
        
% GEBOORTE
        if newPrey.age > birthagePrey
           out=rand;
            if out<probbrirthPrey
                child = struct('x', W(randi([1,numel(W)])), 'y', W(randi([1,numel(W)])), 'age', 0);
                preyid = preyid + 1;
                preyMap(preyid) = child;
                fprintf('      Prooidier %d krijgt kind %d', thep, preyid);
            end    
        end                           
        preyMap(thep) = newPrey;                    
    end

                                  

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% ROOFDIEREN (PREDATORS)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    
    disp('Roofdieren:');
    for q = keys(predMap)
        theq = q{1};
        fprintf('  Roofdier %d\n',theq);
        newPred = predMap(theq);
        fprintf('    Coördinaten: (%.2f, %.2f)', newPred.x, newPred.y)
        newPred.honger = newPred.honger + 1;        

% COÖRDINATEN
        d = rand * rpred;
        rad = rand * 2 * pi;
        
        newpredx = newPred.x + cos(rad) * d;
        newpredy = newPred.y + sin(rad) * d;
        
        while newpredx<0 || newpredx>axis || newpredy<0 || newpredy>axis
            d = rand * rpred;
            rad = rand * 2 * pi;
            newpredx = newPred.x + cos(rad) * d;       
            newpredy = newPred.y + sin(rad) * d;
        end
                     
        newPred.x = newpredx;
        newPred.y = newpredy;
       
% LEEFTIJD
        newPred.age = newPred.age + 1;        
     
% WEERGAVE
        Plaats = sprintf('    Beweegt naar: (%.2f, %.2f)', newPred.x, newPred.y);
        disp(Plaats)
        Leeftijd = sprintf('    Leeftijd: %d', newPred.age);
        disp(Leeftijd) 
       
% GEBOORTE
        if newPred.age > birthagePred
           out=rand;
            if out<probbirthPred
                pred = struct('x', W(randi([1,numel(W)])), 'y', W(randi([1,numel(W)])), 'age', 0, 'honger', 0);
                predid = predid + 1;
                predMap(predid) = pred;
                fprintf('      Roofdier %d krijgt kind %d', theq, predid);
            end    
        end

Answer 1

[Muthaffar A-Jassim]

x^3+3*x-2*x-6