randtensor3

 RANDTENSOR3 - Randomly generates a 3-way low-rank tensor

 Syntax
  function X=randtensor3(sz, dims)

 Reference
 "On the extension of trace norm to tensors"
 Ryota Tomioka, Kohei Hayashi, and Hisashi Kashima
 arXiv:1010.0789
 http://arxiv.org/abs/1010.0789
 
 Copyright(c) 2010 Ryota Tomioka
 This software is distributed under the MIT license. See license.txt

0001 % RANDTENSOR3 - Randomly generates a 3-way low-rank tensor
0002 %
0003 % Syntax
0004 %  function X=randtensor3(sz, dims)
0005 %
0006 % Reference
0007 % "On the extension of trace norm to tensors"
0008 % Ryota Tomioka, Kohei Hayashi, and Hisashi Kashima
0009 % arXiv:1010.0789
0010 % http://arxiv.org/abs/1010.0789
0011 %
0012 % Copyright(c) 2010 Ryota Tomioka
0013 % This software is distributed under the MIT license. See license.txt
0014 
0015 
0016 function X=randtensor3(sz, dims)
0017 
0018 nd=length(sz);
0019 
0020 C=randn(dims);
0021 
0022 U=cell(1,nd);
0023 for jj=1:nd
0024   [U{jj},R]=qr(randn(sz(jj),dims(jj)),0);
0025 end
0026 
0027 X=kolda3(C,U{:});