function [RMS] = LWBtestslow(filename,maxiter)

   load(filename,'-mat');                %image loaded as obj
   [npixels nangles] = size(obj);
   data = project2D(obj,nangles);
   
   alpha = powermethod_LW(npixels,nangles);  %uses obj to estimate relaxation parameter
        
   for i = 1:maxiter
       
       image = Landweber(data,i,alpha);
       predata = project2D(image,nangles);
       dif = data - predata;
       RMS(i) = norm(dif,2)/sqrt(npixels*nangles);
       
   end
   
   index = 1:1:maxiter;
   f1 = figure('Visible','on','Position',[300,200,600,800]);
   plot(index,RMS,'-b','Linewidth',2)