code: @Override
      public ZMatrixRMaj getT(ZMatrixRMaj T ) {
          T = UtilDecompositons_ZDRM.checkZeros(T,N,N);
  
          T.data[0] = QT.data[0];
          T.data[1] = QT.data[1];
  
          for( int i = 1; i < N; i++ ) {
              T.set(i,i, QT.getReal(i,i), QT.getImag(i,i));
              double real = QT.getReal(i-1,i);
              double imag = QT.getImag(i-1,i);
              T.set(i-1,i,real,imag);
              T.set(i,i-1,real,-imag);
          }
  
          return T;
      }
docs: Extracts the tridiagonal matrix found in the decomposition.
  
  @param T If not null then the results will be stored here.  Otherwise a new matrix will be created.
  @return The extracted T matrix.