Jetty Problem

Typical Jetty Problem, problem with my code though? (specifically the line prob = 100 * nsafe / n;) Why doesn't this work?

Also I am trying to graph the probability of survival against the probability of going forward. Help doing this much appreciated!

Here's my code:

% random walk p = input( 'Number of walks: ' );

nsafe = 0; % number of times he makes it

for i = 1:p

steps = 0; % each new walk ...

x = 0; % ... starts at the origin

y = 0;

while x <= 50 & abs(y) <= 10 & steps < 2000

steps = steps + 1; % that’s another step

r = rand; % random number for that step

if r < 0.6 % which way did he go?

x = x + 1; % maybe forward ...

elseif r < 0.8

y = y + 1; % ... or to port ...

else

y = y - 1; % ... or to starboard

end;

end;

if x > 50

nsafe = nsafe + 1; % he actually made it this time!

end;

end;

prob = 100 * nsafe / n;

disp( prob );

Answer 1

[Thomas]

You have not defined 'n' anywhere in your code... what is 'n'?

EDIT based on the comment hat n=number of steps

Change the prob = 100 * nsafe / n; to the following:

prob = 100 * nsafe / steps;

[Reelz]

n is the number of steps. Which if she hasn't reached the ship after 2000 steps she dies of thirst. She can go either forward, left, or right. Basically I am just generating probabilities, how would I edit my code to include this though?

[Thomas]

check my edit above