For-Loop vs While-Loop

I have the code in Part1 below which stores the values of x and y after the last iteration of my while-loop. Is there a way for me to achieve to what I am trying to do in Part2; that is, to retain all values of x and y along the way as the loop is still running/prompting the user for inputs? I have already achieved this with a for-loop, but I need to be able to do this with a while-loop and have hit a wall.

Any ideas? Also, it would be nice to be able to display an error message when the while-condition no longer holds true; the only way I know how to do this is with an if-statement and disp construct, which doesn't seem to be working inside the while-loop (again, I've been able to accomplish this in a for-loop but would like to do it in a while-loop). Any thoughts are welcome.

*

Part1 - Currently have:*
temp=('Enter initial [x y] pair: ');
while isempty(temp)==0
      x=temp(1);
      y=temp(2);
      temp=input('Enter next [x y] pair');
end

*Part2 - Would like to have:*
temp=('Enter initial [x y] pair: ');
while isempty(temp)==0
      x=temp(1);
      y=temp(2);
      temp=input('Enter next [x y] pair');
end

Answer 1

[Image Analyst]

You can have them enter some value that indicates when to quit, like if x or temp is negative of something

if x < 0
  break;
end

or

if temp(1) < 0 || temp(2) < 0
  uiwait(warndlg('Exiting loop because you entered a negative number'));
  break;
end

[Maroulator]

Image Analyst,

Thanks! Any thoughts on the first part of the question, i.e. retaining all values of x and y along the way (in a 1xn array) as the loop is still running/prompting the user for inputs?

[Image Analyst]

Just use a counter that you increment each time:

counter = 1;
while...........
  x(counter) = ..............
  y(counter) = ...............
  counter = counter + 1;
end

[Maroulator]

Nice! Thanks again.