How can I apply the loop method for this program ?

I want create a program that continuously asks the user to enter numbers until the user enters a negative number. The numbers before the last one (non-negative numbers) are saved in a vector B. Then I want to display B and the average value in B. For instance, if the user enters 3, 5, 0, 7, 11, -3, the input stops and B is [3, 5, 0, 7, 11]. The average value of B is 5.2.

I know how to do it with the built-in functions of Matlab, but can not figure out how to do it with the loop method. Help !

Thanks,

Answer 1

[Image Analyst]

Try this:

count = 0;
defaultValue = 45;
titleBar = 'Enter a number';
userPrompt = 'Enter the number';
while count < 100 % failsafe - max amount we ever expect so don't get infinite loop
  % Ask user for a number.
  caUserInput = inputdlg(userPrompt, titleBar, 1, {num2str(defaultValue)});
  if isempty(caUserInput),break,end; % Bail out if they clicked Cancel.
  % Round to nearest integer in case they entered a floating point number.
  theNumber = str2double(cell2mat(caUserInput));
  % Check for a valid integer.
  if isnan(theNumber)
    % They didn't enter a number.
    % They clicked Cancel, or entered a character, symbols, or something else not allowed.
    theNumber = defaultValue;
    message = sprintf('I said it had to be an integer.\nI will use %d and continue.', theNumber);
    uiwait(warndlg(message));
  end
  % Exit if number is negative:
  if theNumber < 0
    break;
  end
  count = count + 1;
  B(count) = theNumber;
end
if count >= 1
  % Display B
  B
  % Display  mean of B
  meanB = mean(B);
  fprintf('The mean of B = %.3f\n', meanB);
end