Iterative loop storing variables

So I'm using a 'while-end' loop for a particular code in MATLAB, the particular criterion to end the loop I'm using is such that the value for a variable between the nth iteration and nth-1 iteration is a pre-defined value.

e.g.

Inputs for: variables, constants, etc.

while: abs(variable 'nth' iteration - variable 'nth-1' iteration) >= pre-defined value

- - - MATLAB CODE HERE - - - ETC.

end

I was just wondering how would I perhaps go about scripting it, do I have to store the variable each iteration and bring it back into the next iteration? I'm struggling to see how to do this exactly, I'm not particularly use to loops in MATLAB.

I would appreciate a push in the right direction!

Conor.

Answer 1

[Cedric]

Here is an example

 a         = 100 ;   % Initial value.
 a_last    = Inf ;
 threshold = 5 ;

 while abs(a - a_last) >= threshold
    % Save previous value of a.
    a_last = a ;

    % Compute new value.
    a = a - sqrt( a ) ;

    % Do whatever else..
    disp( a ) ;
 end