while loop only diving last result

Hi,

I have some code within a while loop. Let's say the loop runs 10 times and I want to find Xstar for each of those 10 times. The code will do this, but I want to create a vector to hold each of these 10 values so I don't have to read through and find them. After the code runs,the value stored onto Xstar is the value for the 10th iteration. I want to keep it that way, but also add a new vector that holds ALL of the Xstar values.

Thank you!!

[Azzi Abdelmalek]

post your code

Answer 1

[Oleg Komarov]

count = 0;                    % initialize counter
out   = zeros(100,1);         % preallocate (not always possible with while)
while count < 100
    count      = count + 1;   % increment counter
    out(count) = rand;        % allocate result into preassigned space in out
end

[Matt Fig]

And if Xstar is not a scalar,

out = cell(100,1);  % Before the loop
...
out{count} = Xstart;  %  In the loop

[Matlabbey]

That seemed to output the final value of Xstar repeatedly. Do I want to put this code outside of the while loop?

The piece of code that finds the value for Xstar is already inside of a while loop...Is it just where I placed your code? I would post it but its thousands and thousands of lines and I'd rather not...

It's something like:

while condition
  thousands of lines of code
   Xstar = equation;
end

It outputs the value of Xstar each time but it would take a long time to look through the output to find the value. Does that make sense?

thank you!

[Walter Roberson]

Xstar = {}
while condition
  thousands of lines of code
  Xstar{end+1} = equation;
end

Note: if you can make reasonable guesses about the number of iterations, it is best to pre-allocate the cell array and use a counter instead of "end+1".

guess_length = 100;
Xstar = cell(guess_length,1);
count = 0;
while condition
  thousands of lines of code
  count = count + 1;
  Xstar{count} = equation;
end
if count < guess_length       %trim off unused portions
  Xstar(counts+1:end) = [];
end

[Matlabbey]

Thanks!! That did the trick!

Answer 2

[Azzi Abdelmalek]

 v=[];

 while condition
 Xstar=
 v=[v Xstar]
 end