How to create a Measurement
 
	    A simple Measurement of type "x" (RP::x) can be created as follows:
	    
	    
	    
	    	    
	     	    	    
	       	    
		// create a position vector at (0,0,0)
	      	    
	      
	      
	      EVector pos(3,0);
	      
	            
	       	    
		// create a vector of one component with value pos[0]
	      	    
	      
	      
	      EVector m(1,0); m[0]=pos[0];      
	      
	    
	       	    
		// create a 1x1 Matrix  with value 0
	      	    
	      
	      	      
	      EMatrix M(1,1,0);    
	      
	    
	       	    
		// square of the x measurement error  
	      	    
	      
	      	      
	      M[0][0] = pow(5*mm,2);              	      
	      
	    
	      
	    
	       	    
		// Create the measurement
	      	      	   
	      
	       	      
	      Measurement* meas = new Measurement();
	      
	    
	       	    
		// Set the mandatory measurement attributes 
		// First the measurement type, which should match the measurement HyperVector
	      	    
	      
	      	      	      
	      meas->set_name(RP::x);
	      
	    
	       	    
		// The measurement HyperVector
	      	    
	      
	      	      	      
	      meas->set_hv(HyperVector(m,M));
	      
	    
	       	    
		// The measurement position. Used for Ordering Measurements inside a Trajectory 
		// and to create measurements surfaces automatically.
	      	    
	      
	    	      
	      meas->set_position(pos);
	    	      	      	      
	    
	    
	    
	    
	    A measurement Surface is optional. This functionality is a bit obsolete and no Surface is needed in principle since 
	    measurements surfaces can be build on the fly using the measurement position and the normal to the surface, which is 
	    a volume property (RP::SurfNormal). To set the surface:
	    
	    
	    
	    	    
	     	    	    
	      meas->set_surface(surf);
	    	      	      	      
	    
	    
	    
	    
	    where surf is a pointer to a   Surface that has being created previously. 
	    
	    
	    
	    
	    The available measurement types are: