placematrix2

 function m1 = placematrix2(m1,m2,pos)

 <m1> is a matrix (cell matrix okay)
 <m2> is a matrix (cell matrix okay)
 <pos> (optional) is [x1 x2 x3 ...] with a position.
   x1, x2, x3, etc. must be positive integers, and
   there must be at least ndims(m2) of these numbers.
   default is ones(1,ndims(m2)).

 place <m2> in <m1> positioned with first element at <pos>.
 <m1> and <m2> must both be of the same type (matrix or cell matrix).
 if <m1> is not large enough to accommodate <m2>, 0s or []s 
 are automatically filled in.

 example:
 isequal(placematrix2([1 2 3; 4 5 6; 7 8 9],[0 0],[2 1]),[1 2 3; 0 0 6; 7 8 9])

0001 function m1 = placematrix2(m1,m2,pos)
0002 
0003 % function m1 = placematrix2(m1,m2,pos)
0004 %
0005 % <m1> is a matrix (cell matrix okay)
0006 % <m2> is a matrix (cell matrix okay)
0007 % <pos> (optional) is [x1 x2 x3 ...] with a position.
0008 %   x1, x2, x3, etc. must be positive integers, and
0009 %   there must be at least ndims(m2) of these numbers.
0010 %   default is ones(1,ndims(m2)).
0011 %
0012 % place <m2> in <m1> positioned with first element at <pos>.
0013 % <m1> and <m2> must both be of the same type (matrix or cell matrix).
0014 % if <m1> is not large enough to accommodate <m2>, 0s or []s
0015 % are automatically filled in.
0016 %
0017 % example:
0018 % isequal(placematrix2([1 2 3; 4 5 6; 7 8 9],[0 0],[2 1]),[1 2 3; 0 0 6; 7 8 9])
0019 
0020 %% SEE ALSO padarray.m ?
0021 
0022 % input
0023 if ~exist('pos','var') || isempty(pos)
0024   pos = ones(1,ndims(m2));
0025 end
0026 
0027 % figure out indices
0028 indices = {};
0029 for p=1:length(pos)
0030   indices{p} = pos(p)-1 + (1:size(m2,p));
0031 end
0032 
0033 % do it
0034 m1(indices{:}) = m2;