perform_tensor_decomp.m

张量投票在matlab环境下的仿真。球型张量及棒型张量的仿真

function [e1,e2,l1,l2] = perform_tensor_decomp(T,order)

% perform_tensor_decomp - perform an eigendecomposition.
%
%   [e1,e2,l1,l2] = perform_tensor_decomp(T);
%
%   'e1(i,j,:)' is the main eigenvector at location (i,j)
%       with associated largest eigenvalue 'l1(i,j)'.
%   'e2(i,j,:)' is the second eigenvector at location (i,j)
%       with associated smallest eigenvalue 'l2(i,j)'.
%
%   So you always have l1>=l2 (not in absolute value !).
%
%   If 'order'=='abs' then the the decomposition is done
%   so that abs(l1)>=abs(l2)
%
%   'T' must be a tensorial field (produced eg. by compute_hessian), 
%   so it should be symmetric.
%
%   Copyright (c) 2004 Gabriel Peyr