There is no 1-to-1 correspondence to the C++ do while loop in MATLAB. Your best option is to use a while loop. The difference is that while loops check the condition at the beginning of the loop while do while loops check the condition at the end of the loop. while (abs(A-B) <= 50) ... end To check the condition at the end of the loop using a while loop, use an if statement inside the while loop: while 1 if ~(abs(A - B) <= 50) break; end end

while(true)

%code

    if condition==false
        break; 
    end 
end

I don't really understand your question. Is there a specific thing you would like help with? For direction, I would start reading up on Matlab's for loop and while loop documentation and look at some examples. Remember, for loops step through an iterative process where you define the end step. While loops iterate until a condition is met.

It looks like you're doing some sort of basic demonstration of exponential behavior, but I'm not really sure how you're trying to go about it. It almost looks like you're using i as your data array while simultaneously thinking of it as an iterator. Are you trying to do something like this? A=5000; B=4000; C=3000; D=2000; E=1000; mdata=[A B C D E] i=1; while mdata(i,5)>0 % we need to be looking at the current line, otherwise nothing changes mdata(1,1)=mdata(1,5); %beginning balance row 2 mdata(1,2)=mdata(1,1)*1.5/12; %interest row 2 mdata(1,3)=mdata(1,2)-mdata(1,3); %principal row 2 mdata(1,4)=mdata(1,1)-mdata(1,4); %ending balance row 2 % but what is column 5? i=i+1; mdata=[mdata;mdata(1,1),mdata(1,2),mdata(1,3),mdata(1,4),mdata(1,5)]; end There's still the question of what column 5 is supposed to be. This line: mdata(1,1)=mdata(1,5); % beginning balance row 2 implies that col5 is the prior ending balance, but this line: mdata(1,4)=mdata(1,1)-mdata(1,4); % ending balance row 2 implies that col4 is the prior ending balance instead. Which is it? If column 5 is never updated, then why does the initial dataset have five columns?