hey guys heres the problem i have to do...im totally stumped.

%% Write a function called sumDigits() that takes in a number and returns
%% the sum of the digits in the number as a single digit number. Your
%% function should sum the digits in the number, and if that sum is greater
%% than 9, then you should repeat the above process till you end up with a
%% single digit.
%%
%% Note: You MUST use iteration to get credit for this problem.
%%
%% Example:
%% sumDigits(34) should return 7 (since 3+4 = 7)
%% sumDigits(345) should return 3 (since 3+4+5 = 12; 2+1 = 3)
%% You can assume that the input will always be positive.

%% The function header is given below:
%% function digit = sumDigits(num)


and here is what i have so far:

function digit = sumDigits(num)
%sumDigits takes a number and adds all of its digits until
%the sum of all digits is a single digit number.
% ex: 15 = 1 + 5 = 6
while(num > 9)
mod(num, 10);
num = floor(num/10)
end
num

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ok so i know theoretically what needs to happen but i cant execute! What i am trying to do is use mod to get the remainder of the last number...then somehow add that to the digit before it. mabye i could create a vector , remove the last digit from the number somehow and put it in the vector... then get the sum of the vector and reciprocate the process...idk what to do.. help Yikes =)

It's been a long time since I've touched matlab, so I don't remember the functions, but you need to parse the digits and dump them into an array. Then sum the array and put it back in the loop.