function retval = quadstop(xold,xnew) % usage: doneflag = quadstop(xold,xnew) % description: tests for successful quadratic stopping criterion % and returns boolean true if successful, false otherwise. % xold: starting point % xnew: new point % global variables: global parms; global countiter; countiter = countiter + 1; maxiter = parms.maxiter; releps = parms.releps; abseps = parms.abseps; ordcoef = parms.ordcoef; retval = 1; if (countiter == maxiter) % too many iterations? disp('Iteration limit reached') else if (norm(xnew-xold)>ordcoef*sqrt(releps)+abseps) retval = 0; end end