jidt/demos/octave/example3TeContinuousDataKer...

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%%
%% Java Information Dynamics Toolkit (JIDT)
%% Copyright (C) 2012, Joseph T. Lizier
%%
%% This program is free software: you can redistribute it and/or modify
%% it under the terms of the GNU General Public License as published by
%% the Free Software Foundation, either version 3 of the License, or
%% (at your option) any later version.
%%
%% This program is distributed in the hope that it will be useful,
%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
%% GNU General Public License for more details.
%%
%% You should have received a copy of the GNU General Public License
%% along with this program. If not, see <http://www.gnu.org/licenses/>.
%%
% = Example 3 - Transfer entropy on continuous data using kernel estimators =
% Simple transfer entropy (TE) calculation on continuous-valued data using the (box) kernel-estimator TE calculator.
% Change location of jar to match yours:
javaaddpath('../../infodynamics.jar');
% Generate some random normalised data.
numObservations = 1000;
covariance=0.4;
sourceArray=randn(numObservations, 1);
destArray = [0; covariance*sourceArray(1:numObservations-1) + (1-covariance)*randn(numObservations - 1, 1)];
sourceArray2=randn(numObservations, 1); % Uncorrelated source
% Create a TE calculator and run it:
teCalc=javaObject('infodynamics.measures.continuous.kernel.TransferEntropyCalculatorKernel');
teCalc.setProperty('NORMALISE', 'true'); % Normalise the individual variables
teCalc.initialise(1, 0.5); % Use history length 1 (Schreiber k=1), kernel width of 0.5 normalised units
teCalc.setObservations(sourceArray, destArray);
% For copied source, should give something close to expected value for correlated Gaussians:
result = teCalc.computeAverageLocalOfObservations();
fprintf('TE result %.4f bits; expected to be close to %.4f bits for these correlated Gaussians but biased upwards\n', ...
result, log(1/(1-covariance^2))/log(2));
teCalc.initialise(); % Initialise leaving the parameters the same
teCalc.setObservations(sourceArray2, destArray);
% For random source, it should give something close to 0 bits
result2 = teCalc.computeAverageLocalOfObservations();
fprintf('TE result %.4f bits; expected to be close to 0 bits for uncorrelated Gaussians but will be biased upwards\n', ...
result2);