gravity obtained as above is sought step s4 this distance is not an euclidean distance but one defined as as follows particularly as shown in fig7 the distance in question is defined as a half length l of the minor axis of an ellipse 18 having its center located at the initial center of gravity g of each cluster and its major axis tilted by an angle u03b8 and passing the blood cell 16 in question the tilt angle u03b8 is peculiar to each cluster and determined previously in experimental fashion the reason why the distance is defined as above is that the shape of distribution of each cluster of blood cells is elliptic and therefore all blood cells lying on the same ellipse should have the same distance from the center of gravity the calculation of the distance l is effected as follows defining co ordinate axes x 34 and y 34 along the major and minor axes of the ellipse 18 respectively and assuming kl k is a proportional constant as the major axis of the ellipse 18 then the equation of the ellipse is given as follows in connection with these co ordinate axes equ2 this equation can be solved as follows as looking.