TT-Toolbox (TT=Tensor Train) Version 2.2.2 TT(Tensor Train) format is an efficient way for low-parametric representation of high-dimensional tensors. The TT-Toolbox is a MATLAB implementation of basic operations with tensors in TT-format. It includes: * tt_tensor and tt_matrix classes for storing vectors and operators * Basic linear algebra subroutines (addition, matrix-by-vector product, elementwise multiplication and many others) using standard MATLAB syntax, linear complexity in the dimension, reshape function * Fast rounding procedure with a prescribed accuracy * Advanced approximation and solution techniques: * Approximate solution of linear systems and eigenvalue problems * Cross methods to approximate ``black-box'' tensors * Wavelet tensor train decomposition * Construction of basic operators and functions (Laplace operator, function of a TT-tensor) * Computation of maximal and minimal elements of a tensor * and several others New in Version 2.2.2 * one-element MATLAB-style subsref and subsassgn now possible for tt_matrix: current_value=ttm(123,4567) and ttm(123,4567)=new_value * submatrix extraction is now possible: ttm2=ttm([1 2 7],[1 2 1;1 1 2]) For additional help see code of @tt_matrix/subsref.m and core/tt_submatrix.m New in Version 2.2.1 * Blockwise assembly of tt_matrices added: ttM=tt_blockwise({ttA ttB ttC;ttD ttE ttF}) * subtensor extraction is now possible: ttv2=ttv(1,2,:,2,2,:,:,:,1) or ttv2=ttv({1,2,':',2,2,':',':',':',1}) For additional help see code of @tt_tensor/subsref.m and core/tt_subtensor.m New in Version 2.2 * Better documentation * Mixed QTT-Tucker format (qtt_tucker class) * reshape function for a TT-tensor/TT-matrix * dmrg_cross method for black-box tensor approximation * Convolution in QTT-format TT-Toolbox 2.2. can be downloaded from http://spring.inm.ras.ru/osel