Multiple Dice Rolls Help

So basically, I have to write a function that simulates the rolling of a

given number of six sided dice a given number of times. The function should

take

two input arguments, the number of dice (NumDice) that will be rolled in each

experiment and the total number (NumRolls) of times that the dice will be

rolled. The output of the function will be a vector SumDice of length NumRolls

that contains the sum of the dice values in each experiment. I'll have to make

a histogram afterwards (which I havent done yet)

Here's what I've got so far, not sure how to make it a sum of dice:

    % function SumDice=RollDice(NumDice,NumRolls)
distribution=zeros(6,1);
for roll=1:NumRolls
    diceValues = randi(6,[NumDice 1]);
    for die = 1 : NumDice
    distribution(diceValues(die)) = distribution(diceValues(die)) +1;
  end
end

Answer 1

[Walter Roberson]

Sum of dice is just sum(diceValues). And you will not need the "for die" loop as you only get a single sum.

(By the way, the entire function can be done as a single expression, including the histogram.)

[SB]

That sounds really interesting, how would you do that?

[Walter Roberson]

randi() can generate all the trials at once. You can then vectorize the summation. Then calculate the histogram on those sums.

[SB]

Could you maybe show an example? Vectorizing the summation as in within a vector using recursion or something?

[Walter Roberson]

sum() can be applied to arrays, not just to vectors.

Answer 2

[Harshit]

Here is what I feel will work fine

% function SumDice=RollDice(NumDice,NumRolls)
distribution=zeros(NumDice*6,1);
for roll=1:NumRolls
  diceValues = randi(6,[NumDice 1]);
  totaldiceValue = sum(diceValues);
    distribution(totaldiceValue) = distribution(totaldiceValue) +1;
  end
end

[nazar youssef]

how to call the function?