ABSTRACT

Then, $ is a projective map if xg = p0£o + -----h pmx m is mapped onto ya = q0 cr0 X0 + • * • + qmamxm. In matrix notation this projective map 3> : * *—► y is written as

Note that some of the q’s or y can be allowed to be ©, which means that $ is allowed to map into V n U {©}. However, if q* ^ © one has to require that ^ 0 since the z-th column of P must represent the point .