function disp_diff(A,B,s1,s2)
% disp_diff(A,B)
% disp_diff(A,B,s1,s2)
% 
% Display recursively all differences between matrices A and B.
% A and B may be nested structures and cell arrays.
% s1 and s2 are optional names of the arguments.
% Only numeric, string, structures, and cell types supported.
% Jan Mandel, 2001  last updated Jan 16 2002
%
% This software is available under GNU General Public License.
% It may be distributed free of charge only, with the source form included, 
% the original source acknowledged, and this license notice included. 
% See http://www.gnu.org/copyleft/gpl.html for details.
% There is no warranty of any kind.

if ~exist('s1','var'),
    s1=inputname(1);
end
if isempty(s1),
   s1='arg1';
end
if ~exist('s2','var'),
    s2=inputname(2);
end
if isempty(s2),
   s2='arg2';
end
if isstruct(A),
   if ~isstruct(B),
      fprintf('%s is not a structure\n',s2)
   else
      f=fieldnames(A);
      for i=1:length(f),
         if isfield(B,f{i}),
            disp_diff(getfield(A,f{i}),getfield(B,f{i}),[s1,'.',f{i}],[s2,'.',f{i}])
         else
            fprintf('%s.%s does not exist\n',s2,f{i})
         end
      end
      f=fieldnames(B);
      for i=1:length(f),
         if ~isfield(A,f{i}),
            fprintf('%s.%s does not exist\n',s1,f{i})
         end
      end   
  	end
elseif iscell(A),
   if iscell(B),
      % fprintf('comparing cell %s\n',s)
      ma=size(A);
      mb=size(B);
      if all(ma == mb),
         for i=1:ma(1),
            for j=1:ma(2),
               disp_diff(A{i,j},B{i,j},sprintf('%s{%i,%i}',s1,i,j),sprintf('%s{%i,%i}',s2,i,j))
            end
         end
      else
         fprintf('size differs: %s [%i %i] %s [%i %i]\n',s1,ma,s2,mb)
      end
   else
      fprintf('%s is not a cell')
   end
elseif isnumeric(A),
   if isnumeric(B),
      % fprintf('comparing numeric %s\n',s)
      ma=size(A);
      mb=size(B);
      difdim=1;
      if all(size(ma) == size(mb)), 
         if all(ma == mb)
            difdim=0;
            if all(ma > 0),
                d=big(A-B);
                nd=full(sum(sum(A~=B)));
                nz=max(nnz(A),nnz(B));
                if d,
                    fprintf(['%s %s size %i %i: difference %g relative %g\n',...
                    ' matrices differ in %g place(s) from %g nonzeros\n'],...
                    s1,s2,ma,d,d/max(big(A),big(B)),nd,nz)
                end
            end
          end
       end
       if difdim,
            fprintf('size differs: %s [%s] %s [%s]\n',s1,num2str(ma),s2,num2str(mb))
       end
   else
      fprintf('%s is not numeric',s2)
   end
elseif ischar(A),
   if ischar(B),
      if ~strcmp(A,B),
         fprintf('strings differ: %s=%s %s=%s\n',s1,A,s2,B)
      end
   end
else
   fprintf('%s: unsupported matrix type\n',s1)
end
return

function m=big(a)
m=full(max(abs(a(:))));
return