subscript

 function varargout = subscript(m,range,wantc)

 <m> is a matrix (of numbers) or a string referring to a matrix
   variable in the base workspace.  cell matrices are okay.
 <range> is:
   (1) vector index range that does not use
       the 'end' keyword, e.g., 4, [5 6]
   (2) a logical indexing matrix
   (3) the string ':'
   (4) a cell vector where elements can be of types (1), (2), (3),
       e.g., {':' 4:5}
 <wantc> (optional) is whether to perform cell de-referencing.  default: 0.

 return something like m(range), or m{range} when <wantc>.

 this function is useful for cases where you want
 to get a range of elements from something that
 already has parentheses or brackets.
 it is also useful for working with string-variable
 representations of matrices.  it is also useful
 for writing functions that make no assumption about
 the size of the matrices used as input.

 example:
 isequal(size(subscript(randn(10,10),{1:2 ':'})),[2 10])
 a = [1 2; 3 4];
 subscript('a',1)
 subscript('a',a<1.5)

0001 function varargout = subscript(m,range,wantc)
0002 
0003 % function varargout = subscript(m,range,wantc)
0004 %
0005 % <m> is a matrix (of numbers) or a string referring to a matrix
0006 %   variable in the base workspace.  cell matrices are okay.
0007 % <range> is:
0008 %   (1) vector index range that does not use
0009 %       the 'end' keyword, e.g., 4, [5 6]
0010 %   (2) a logical indexing matrix
0011 %   (3) the string ':'
0012 %   (4) a cell vector where elements can be of types (1), (2), (3),
0013 %       e.g., {':' 4:5}
0014 % <wantc> (optional) is whether to perform cell de-referencing.  default: 0.
0015 %
0016 % return something like m(range), or m{range} when <wantc>.
0017 %
0018 % this function is useful for cases where you want
0019 % to get a range of elements from something that
0020 % already has parentheses or brackets.
0021 % it is also useful for working with string-variable
0022 % representations of matrices.  it is also useful
0023 % for writing functions that make no assumption about
0024 % the size of the matrices used as input.
0025 %
0026 % example:
0027 % isequal(size(subscript(randn(10,10),{1:2 ':'})),[2 10])
0028 % a = [1 2; 3 4];
0029 % subscript('a',1)
0030 % subscript('a',a<1.5)
0031 
0032 % input
0033 if ~exist('wantc','var') || isempty(wantc)
0034   wantc = 0;
0035 end
0036 
0037 % do it
0038 if wantc
0039   if iscell(range)
0040     if ischar(m)
0041       varargout = evalin('base',['subscript(',m,',',cell2str(range),',1);']);
0042     else
0043       varargout = m(range{:});
0044     end
0045   else
0046     if ischar(m)
0047       if ischar(range) && isequal(range,':')
0048         varargout = evalin('base',[m,'(:);']);
0049       else
0050         varargout = evalin('base',[m,'(',mat2str(range),');']);
0051       end
0052     else
0053       if ischar(range) && isequal(range,':')
0054         varargout = m(:);
0055       else
0056         varargout = m(range);
0057       end
0058     end
0059   end
0060 else
0061   varargout = cell(1,1);
0062   if iscell(range)
0063     if ischar(m)
0064       varargout{1} = evalin('base',['subscript(',m,',',cell2str(range),');']);
0065     else
0066       varargout{1} = m(range{:});
0067     end
0068   else
0069     if ischar(m)
0070       if ischar(range) && isequal(range,':')
0071         varargout{1} = evalin('base',[m,'(:);']);
0072       else
0073         varargout{1} = evalin('base',[m,'(',mat2str(range),');']);
0074       end
0075     else
0076       if ischar(range) && isequal(range,':')
0077         varargout{1} = m(:);
0078       else
0079         varargout{1} = m(range);
0080       end
0081     end
0082   end
0083 end