MATLAB: Not sure why the code results in a wrong figure. I am trying to simulate 2 dice rolls and counting how many times it takes to roll 2 6s out 10000 trials.

homeworkMATLABmonte carlo

num_trial=10000;

num_until_success=1;

counter=[];

success_count=0;

for i=1:num_trial

success_count=0;

num_until_success=0;

while success_count==0

roll_1=randi(6,1);

roll_2=randi(6,1);

num_until_success=num_until_success + 1;

if roll_1==6 && roll_2==6

success_count=1;

end

histogram(success_count,10);

xlabel('Number of consecutive rolls until two 6s')

ylabel('Number of occurences')

Best Answer

Hello Enkhdul Batkhuyag,

Try this one -

num_trial=10000;
num_until_success=0;
for i=1:num_trial,i
    roll_1=randi(6,1);roll_1
    roll_2=randi(6,1);roll_2
    if roll_1==6 && roll_2==6
        num_until_success=num_until_success + 1;
    end
end
disp(num_until_success)

Related Solutions

MATLAB: How do you write a command for two loops

Try this:

rng('shuffle')
numRolls=input('Please enter how many rolls you would like to simulate:')
counts = zeros(1, 12);
numDice = 2;
for r = 1 : numRolls
    roll = randi([1 6],1,numDice);
    theSum = sum(roll);
    counts(theSum) = counts(theSum) + 1;
end
counts = (counts / numRolls) * 100

MATLAB: Monte Carlo Simulation – pair of dice roll

You are supposed to count the number of rolls it takes to get boxcars, not the number of boxcars you get in N rolls. So for each trial you are going to roll the dice as many times as it takes to get boxcars. Then you move on to the next trial. Your looping would look something like this:

for i=1:N
    % code goes here to roll the dice over and over again until you get boxcars
    % then record how many rolls it takes in an array.
end

So, instead of a single number count, make count an array with the definition

count(1) = the number of times it took only one roll to get boxcars

count(2) = the number of times it took two rolls to get boxcars

count(3) = the number of times it took three rolls to get boxcars

etc.

Suppose you use a variable called rolls inside your loop to keep track of the number of rolls it takes to get boxcars for that particular trial, then inside your loop you would at some point have this line when you finally get the boxcars:

count(rolls) = count(rolls) + 1;

Rolling the dice over and over again would probably be best with a while-loop. E.g.,

% initialize the rolls counter here
while( true )
    % code to roll the dice one time here
    % increment the rolls counter here
    if( test to see if you got boxcars here )
            % increment the appropriate counts element here
            % exit the while loop
    end
end

Does this outline make sense to you? Then after the for-loop you would just do this:

histogram(count);

Best Answer

Related Solutions

MATLAB: How do you write a command for two loops

MATLAB: Monte Carlo Simulation – pair of dice roll

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