loadmulti

 function f = loadmulti(m,var,dim,gentle)

 <m> is a pattern that matches one or more .mat files (see matchfiles.m)
 <var> is a variable name
 <dim> (optional) is
   N means the dimension along which to concatenate
   0 means do not concatenate; instead, successively merge
     in new versions of <var>.  there are two cases:
     if <var> is a regular matrix, NaN elements get 
     overwritten with new content.  if <var> is a cell 
     matrix, elements that are [] get overwritten with
     new content.  note that the dimensions
     of <var> should be the same in each file.
     however, if they aren't, that's okay --- we 
     automatically expand to the bottom and the right
     as necessary.
   default: 0.
 <gentle> (optional) is
   0 means die if <var> is not found in a given file.
   1 means continue on (and do not crash) if <var> is
     not found in a given file.
   default: 0.

 get <var> from the file(s) named by <m> and either
 concatenate different versions together or merge 
 different versions together.

 we issue a warning if no files are named by <m>.

 we report progress to the command window if the load
 takes longer than 10 seconds.

 example:
 a = {1 2 []};
 save('atest1.mat','a');
 a = {[] 5 3};
 save('atest2.mat','a');
 isequal(loadmulti('atest*mat','a',0),{1 2 3})

0001 function f = loadmulti(m,var,dim,gentle)
0002 
0003 % function f = loadmulti(m,var,dim,gentle)
0004 %
0005 % <m> is a pattern that matches one or more .mat files (see matchfiles.m)
0006 % <var> is a variable name
0007 % <dim> (optional) is
0008 %   N means the dimension along which to concatenate
0009 %   0 means do not concatenate; instead, successively merge
0010 %     in new versions of <var>.  there are two cases:
0011 %     if <var> is a regular matrix, NaN elements get
0012 %     overwritten with new content.  if <var> is a cell
0013 %     matrix, elements that are [] get overwritten with
0014 %     new content.  note that the dimensions
0015 %     of <var> should be the same in each file.
0016 %     however, if they aren't, that's okay --- we
0017 %     automatically expand to the bottom and the right
0018 %     as necessary.
0019 %   default: 0.
0020 % <gentle> (optional) is
0021 %   0 means die if <var> is not found in a given file.
0022 %   1 means continue on (and do not crash) if <var> is
0023 %     not found in a given file.
0024 %   default: 0.
0025 %
0026 % get <var> from the file(s) named by <m> and either
0027 % concatenate different versions together or merge
0028 % different versions together.
0029 %
0030 % we issue a warning if no files are named by <m>.
0031 %
0032 % we report progress to the command window if the load
0033 % takes longer than 10 seconds.
0034 %
0035 % example:
0036 % a = {1 2 []};
0037 % save('atest1.mat','a');
0038 % a = {[] 5 3};
0039 % save('atest2.mat','a');
0040 % isequal(loadmulti('atest*mat','a',0),{1 2 3})
0041 
0042 % internal constants
0043 toolong = 10;  % seconds
0044 
0045 % input
0046 if ~exist('dim','var') || isempty(dim)
0047   dim = 0;
0048 end
0049 if ~exist('gentle','var') || isempty(gentle)
0050   gentle = 0;
0051 end
0052 
0053 % transform
0054 m = matchfiles(m);
0055 
0056 % check sanity
0057 if length(m)==0
0058   warning('no file matches');
0059   f = [];
0060   return;
0061 end
0062 
0063 % do it
0064 stime = clock; didinit = 0; isfirst = 1;
0065 for p=1:length(m)
0066 
0067   % report status
0068   if etime(clock,stime) > toolong
0069     if didinit
0070       statusdots(p,length(m));
0071     else
0072       didinit = 1;
0073       fprintf('loadmulti');
0074     end
0075   end
0076 
0077   % get values from the file
0078   loaded = load(m{p},var);
0079   varnames = fieldnames(loaded);
0080   if isempty(varnames)
0081     if gentle==0
0082       error(sprintf('loadmulti: <var> was not found in some particular file (%s)',m{p}));
0083     end
0084   else
0085     vals = getfield(loaded,varnames{1});
0086   
0087     % special case
0088     if dim==0
0089       
0090       if isfirst
0091         f = vals;
0092         isfirst = 0;
0093       else
0094         [f,vals] = equalizematrixdimensions(f,vals);
0095         if iscell(f)
0096           ix = cellfun(@isempty,f);
0097         else
0098           ix = isnan(f);
0099         end
0100         f(ix) = vals(ix);
0101       end
0102   
0103     % usual case
0104     else
0105       if isfirst
0106         f = vals;
0107         isfirst = 0;
0108       else
0109         f = cat(dim,f,vals);
0110       end
0111     end
0112   end
0113 
0114 end
0115 
0116 % report
0117 if etime(clock,stime) > toolong
0118   fprintf('done.\n');
0119 end