how to do random walk?

1. Write a function xrand(x) which takes as input a number from 0 to 100 and as output returns 1 with likelihood x% and returns -1 with likelihood (100 - x)%. For example, if you evaluate wrand(70.8) one hundred thousand times, you should see approximately 70,800 1s and 29,200 -1s. (Make sure your function works even if w is not an integer.)

2. Write a “weighted” random walk rwalk(n,x) which continues until it is a distance of n from the origin and where the steps are taken using the wrand(x) function. (You should not be typing any of the same code from wrand in this function. Instead you should just be typing “wrand”, which will use the function you’ve just written.)

[James Tursa]

What have you done so far? What specific problems are you having with your code?

[siemcheng ngor]

this is what i have done so far, but it only work for integer and only always gives me -1 for whatever value i input.

function []=wrand(w)
  for i = 0:100
      if w==rand(w)
          w=1;
      else w==(100-w);
          w=-1;
      end
  end
  disp(w)
  end

[Jos (10584)]

Think about:

• what does the statement rand(w) return
• when does w==rand(w) evaluate to true?
• how many statements are there in the else-block?

Answer 1

[Image Analyst]

I have a few random walk demos. You might look them over. Adapt as needed if they look close to what you want.

[Natesha Alexander]

I am trying to simulate a symmetric random walk on a line where deltax and delta t =0.1

[Image Analyst]

OK, good luck.

If you ever do have a question, post in a new link with your code.