util_get_resp.m

Standard model object recognition matlab code

function r_out = util_get_resp (dn, param)

% FUNCTION r_out = util_get_resp (dn, param)
%
% Get random unit's responses from a directory named dn.  The input
% arguement param determines how many model units from which layers
% to pick.  For example, if dn = 'Test', and param = [0 100 0 200],
% then 100 and 200 random responses from Animal/Layer2 and
% Animal/Layer4 directories will be retrieved for each stimulus
% image.  For exmaple,
%  r_out = util_get_resp ('Animal', [0 100 0 200]);
%
% The output r_out is a structure with fields r_out.layerX,
% which is a number of features (defined by param) by number of
% images (determined by the number of files in the directory).
%
% If the requested number is too many (over 1000000), all units are chosen.

BigNUM = 1000000;

if ~exist(dn, 'dir')
   error(['No such directory: ' dn]);
end

r_out = [];

for layer = 1:length(param) % loop thru layers
   if param(layer) > 0
      dn_layer = [dn '/Layer' num2str(layer) '/'];

      D        = dir([dn_layer 'r_i*.mat']);
      disp(['Getting response from ' dn_layer]);

      for i = 1:length(D) % loop thru files
         fprintf('.');
         if mod(i,50)==0
            fprintf('\n');
         end

         clear r r_all;
         load([dn_layer D(i).name]);
         % r_all is (x times y times scales) by (num_features).
         r_all = aux_get_all_resp(r);

         if i == 1 % Load the saved random picks?
            if param(layer)>BigNUM % Too many neurons, then pick all.
               filename = ['rand_pick_L' num2str(layer) '_all.mat'];
            else
               filename = ['rand_pick_L' num2str(layer) '_'];
               filename = [filename num2str(param(layer)) '.mat'];
            end

            if ~exist(filename,'file')
               % Decide which units to pick.  Note that this random pick
               % is the same for a given directory, but if the user
               % runs this function again, another random set will be
               % picked.
               num_units = size(r_all,1) * size(r_all,2);
               if num_units > param(layer)
                  % If the number of possible units is greater than
                  % requested number of units, then go ahead with random pick.
                  x = randperm(num_units);
                  rand_pick = x(1:param(layer));
               else
                  rand_pick = [1:num_units];
                  filename = ['rand_pick_L' num2str(layer) '_all.mat'];
               end
               save(filename, 'rand_pick');
            else
               load(filename);
            end
            r_tmp = zeros(length(rand_pick),length(D));
         end
         r_tmp(:,i) = r_all(rand_pick);
      end
      fprintf('\n');
      r_out = setfield(r_out, ['Layer' num2str(layer)], r_tmp);
      clear r_tmp;
   end
end