Repeating a loop/iteration in a for loop (for adaptive time stepping)

Hi,

I am trying to write a code for adaptive time stepping using the explicit euler method.

I was wondering if there is a way to repeat an iteration for a 'for' loop which has an if-else statement like this:

if error is greater than tolerance

   Throw current results away, and decrease time step using a specific formula and redo calculations for the current iteration

Else

    Accept results and calculate new increased time step, and continue with calculations for next iteration

end

Thank you for the help!

Regards

Ushnik