use empty input for identitysigma

demo.m

@@ -9,7 +9,7 @@
 startup
 rng('shuffle', 'twister') % randomize the seed
 
-surrogate_type = 'surrogate-TNC';
+surrogate_type = 'surrogate-T';
 % this data is a preprocessed version of the data available online from 
 % http://stat.columbia.edu/~cunningham/pdf/ChurchlandNature2012_code.zip
 load exampleData.mat 
@@ -23,15 +23,16 @@
 numSurrogates = 100;
 params = [];
 
+
 if strcmp(surrogate_type, 'surrogate-T')
     params.margCov{1} = targetSigmaT;
-    params.margCov{2} = eye(size(dataTensor,2))*(trace(targetSigmaT)/size(dataTensor,2));
-    params.margCov{3} = eye(size(dataTensor,3))*(trace(targetSigmaT)/size(dataTensor,3));
+    params.margCov{2} = [];
+    params.margCov{3} = [];
     params.meanTensor = M.T;
 elseif strcmp(surrogate_type, 'surrogate-TN')
     params.margCov{1} = targetSigmaT;
     params.margCov{2} = targetSigmaN;
-    params.margCov{3} = eye(size(dataTensor,3))*(trace(targetSigmaT)/size(dataTensor,3));
+    params.margCov{3} = [];
     params.meanTensor = M.TN;
 elseif strcmp(surrogate_type, 'surrogate-TNC')
     params.margCov{1} = targetSigmaT;

genTME/fitMaxEntropy.m

@@ -37,8 +37,19 @@
 eigVectors = cell(tensorSize, 1);                                          % eigenVectors of each of the specified marginal covariances
 eigValues = cell(tensorSize, 1);                                           % eigenValues of each of the specified marginal covariances
 trSigma = nan(tensorSize, 1);                                              % sum of each of the eigenValues of each of the specified marginal covariances
+dim = size(maxEntropy.meanTensor);
+for i = 1:tensorSize
+    if ~isempty(margCov{i})
+       Tr = trace(margCov{i});
+       break
+    end
+end
+
 for i = 1:tensorSize                                                       % load all the inputs
     Sigma = margCov{i};
+    if isempty(Sigma)
+        Sigma = eye(dim(i))*(trace(Tr)/dim(i));
+    end
     dim(i) = size(Sigma,1);
     [Q, S] = svd(Sigma);
     [S, ix] = sort(diag(S), 'descend');