Counting the number 6s rolled from a dice

I was trying to get my code to count the number of 6s rolled from 1000 attempts from a dice however it keeps saying it has not rolled a single 6.

X= floor(rand(1,1000)*6)+1;

if X==6

y = y + 1

end

y

>> Week3Q1

y =

0

Why does it display 0 even though a 6 must have been rolled? Help would be appreciated.

Answer 1

[Dyuman Joshi]

You can also use randi to generate the data as well -

X = randi([1 6], 1, 1000);

The "if" statement is only executed when all of the inputs are true -

if [true false]
    disp('Hey')
elseif [true true true]
    disp('Hello')
end

Hello

What you want to do is to go through each value in X and compare it to 6 -

y = 0;
for k=1:numel(X)
    if X(k)==6
        y = y+1;
    end
end
y

y = 183

You can also do it directly like this -

Y = sum(X==6)

Y = 183

%or
Y = nnz(X==6)

Y = 183

[Nathan]

Thank you! This was helpful as my code works now

[Dyuman Joshi]

Glad to have helped!

[Torsten]

@Nathan

If you want to use "rand" to simulate your experiment, you can interprete the event that "rand" gives a value in between 5/6 and 1 as a "six" for the dice roll.

rng("default")
X = rand(1,10000);
n = nnz(X >= 5/6);
n/10000

ans = 0.1639

1/6

ans = 0.1667