subsref

 SUBSREF Subscripted reference
 An overloaded function...
 _________________________________________________________________________________
 Copyright (C) 2005 Wellcome Department of Imaging Neuroscience

0001 function varargout=subsref(obj,subs)
0002 % SUBSREF Subscripted reference
0003 % An overloaded function...
0004 % _________________________________________________________________________________
0005 % Copyright (C) 2005 Wellcome Department of Imaging Neuroscience
0006 
0007 %
0008 % $Id: subsref.m 315 2005-11-28 16:48:59Z john $
0009 
0010 
0011 if isempty(subs)
0012     return;
0013 end;
0014 
0015 if ~strcmp(subs(1).type,'()'),
0016     if strcmp(subs(1).type,'.'),
0017         %error('Attempt to reference field of non-structure array.');
0018         %if numel(struct(obj))~=1,
0019         %    error('Can only access the fields of simple file_array objects.');
0020         %end;
0021 
0022         varargout = access_fields(obj,subs);
0023         return;
0024     end;
0025     if strcmp(subs.type,'{}'), error('Cell contents reference from a non-cell array object.'); end;
0026 end;
0027 
0028 if numel(subs)~=1, error('Expression too complicated');end;
0029 
0030 dim  = [size(obj) ones(1,16)];
0031 nd   = max(find(dim>1))-1;
0032 sobj = struct(obj);
0033 
0034 if length(subs.subs) < nd,
0035     l   = length(subs.subs);
0036     dim = [dim(1:(l-1)) prod(dim(l:end))];
0037     if numel(sobj) ~= 1,
0038         error('Can only reshape simple create_file_array objects.');
0039     else
0040         if numel(sobj.scl_slope)>1 || numel(sobj.scl_inter)>1,
0041             error('Can not reshape create_file_array objects with multiple slopes and intercepts.');
0042         end;
0043         sobj.dim = dim;
0044     end;
0045 end;
0046 
0047 do   = ones(16,1);
0048 args = {};
0049 for i=1:length(subs.subs),
0050     if ischar(subs.subs{i}),
0051         if ~strcmp(subs.subs{i},':'), error('This shouldn''t happen....'); end;
0052         args{i} = int32(1:dim(i));
0053     else
0054         args{i} = int32(subs.subs{i});
0055     end;
0056     do(i) = length(args{i});
0057 end;
0058 
0059 if length(sobj)==1,
0060     t = subfun(sobj,args{:});
0061 else
0062     t = zeros(do');
0063     for j=1:length(sobj),
0064         ps = [sobj(j).pos ones(1,length(args))];
0065         dm = [sobj(j).dim ones(1,length(args))];
0066         for i=1:length(args),
0067             msk      = find(args{i}>=ps(i) & args{i}<(ps(i)+dm(i)));
0068             args2{i} = msk;
0069             args3{i} = int32(double(args{i}(msk))-ps(i)+1);
0070         end;
0071 
0072         t  = subsasgn(t,struct('type','()','subs',{args2}),subfun(sobj(j),args3{:}));
0073     end
0074 end
0075 varargout = {t};
0076 return;
0077 
0078 function t = subfun(sobj,varargin)
0079 %sobj.dim = [sobj.dim ones(1,16)];
0080 t = file2mat(sobj,varargin{:});
0081 if ~isempty(sobj.scl_slope) || ~isempty(sobj.scl_inter)
0082     slope = 1;
0083     inter = 0;
0084     if ~isempty(sobj.scl_slope), slope = sobj.scl_slope; end;
0085     if ~isempty(sobj.scl_inter), inter = sobj.scl_inter; end;
0086     if numel(slope)>1,
0087         slope = resize_scales(slope,sobj.dim,varargin);
0088         t     = double(t).*slope;
0089     else
0090         t     = double(t)*slope;
0091     end;
0092     if numel(inter)>1,
0093         inter = resize_scales(inter,sobj.dim,varargin);
0094     end;
0095     t = t + inter;
0096 end;
0097 return;
0098 
0099 function c = access_fields(obj,subs)
0100 %error('Attempt to reference field of non-structure array.');
0101 %if numel(struct(obj))~=1,
0102 %    error('Can only access the fields of simple file_array objects.');
0103 %end;
0104 c    = {};
0105 sobj = struct(obj);
0106 for i=1:numel(sobj),
0107     %obj = class(sobj(i),'file_array');
0108     obj = sobj(i);
0109     switch(subs(1).subs)
0110     case 'fname',     t = fname(obj);
0111     case 'dtype',     t = dtype(obj);
0112     case 'offset',    t = offset(obj);
0113     case 'dim',       t = dim(obj);
0114     case 'scl_slope', t = scl_slope(obj);
0115     case 'scl_inter', t = scl_inter(obj);
0116     otherwise, error(['Reference to non-existent field "' subs(1).type '".']);
0117     end;
0118     if numel(subs)>1,
0119         t = subsref(t,subs(2:end));
0120     end;
0121     c{i} = t;
0122 end;
0123 return;
0124