MATLAB: How to draw the graph of the same function several times

for loopfunctionhold onplottingrandom walk

clear clc

x_t(1) = 0; 
N = 10^2;
for t = 1:N
    xlabel('t'), ylabel('x_t'), title('Random Walk')
    a = sign(randn);
    x_t(t+1) = x_t(t) + a; 
    plot(x_t,'b-')
    hold on
    pause(0.05);
end

How do I plot this same function several times? This is a random walk, every time it gets plotted I want it to look differently, which is exactly what sign(randn) does.

Best Answer

M = 10 ;
N = 10^2;
x_t = zeros(M,N) ;
x_t(:,1) = rand ;
for i = 1:M
    for t = 2:N
          a = sign(randn);
          x_t(i,t) = x_t(i,t-1) + a;
      end
  end
plot(x_t)
xlabel('t'), ylabel('x_t'), title('Random Walk')

It can be easily vectorised.

Related Solutions

MATLAB: Plot the same function several times in one go (Random walk)

You should always include a link to the old question, so people can look there for context. Of course it is always best to use vectorized code. It is a bad idea to refuse that kind of speed increasing measures. But if you are adamant about not using that other solution, just wrap this code in a for loop if you want to repeat it.

 clear variables
 clc
==================
 N = 10; % number of steps.
 M = 10;
 for m=1:M
 x_t(1) = 0;
    for n = 1:N
        a = sign(randn);
        x_t(n+1) = x_t(n) + a;
    end
 plot(x_t);hold on
 end
 xlabel('t'), ylabel('x_t'), title('randomwalk');

MATLAB: Double for loop in a random walk. How to loop over all particles simultaneously instead of looping the amount of steps for each separate particle one at a time

If you want to change the order of the loops, then your x_t and y_t need to be 2d matrices

x_t = zeros(M, N+1);
y_t = zeros(M, N+1);
for n = 1:N
   for m = 1:M
      distance = inf;
      while distance > radie
          x_t(m, n+1) = x_t(m, n) + (-1).^randi(2);
          y_t(m, n+1) = y_t(m, n) + (-1).^randi(2);
          distance = hypot(x_t(m, n+1), y_t(m, n+1));
      end
   end
end
plot(x_t, y_t, 'Markersize', 10);

Best Answer

Related Solutions

MATLAB: Plot the same function several times in one go (Random walk)

MATLAB: Double for loop in a random walk. How to loop over all particles simultaneously instead of looping the amount of steps for each separate particle one at a time

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