code: protected void createLinearSystem( List<AssociatedTriple> observations ) {
  		int N = observations.size();
  
  		A.reshape(4*N,27);
  		A.zero();
  
  		for( int i = 0; i < N; i++ ) {
  			AssociatedTriple t = observations.get(i);
  
  			N1.apply(t.p1,p1_norm);
  			N2.apply(t.p2,p2_norm);
  			N3.apply(t.p3,p3_norm);
  
  			insert(i,0 , p1_norm.x); // tensor 1
  			insert(i,1 , p1_norm.y); // tensor 2
  			insert(i,2 ,1); // tensor 3
  		}
  	}
docs: Constructs the linear matrix that describes from the 3-point constraint with linear
  dependent rows removed