touches the unit cube at 6 points of ±( ρ・1 , ρ・2 , ρ・3 ) where ・ = 1,2,3. (For k-dimensions, the hyper-ellipsoid touches the unit hyper-cube at 2×k points of of ±( ρ・1 , ρ・2 ,.., ρ・k ) where ・ = 1,2,..,k. x y z ( 1 , 0.3 , 0.5 ) ( 0.3 , 1 , 0.7 ) ( 0.5 , 0.7 , 1 ) ρ-matrix herein is, 1 0.3 0.5 0.3 1 0.7 0.5 0.7 1 (-0.5 ,-0.7 ,-1 ) (-0.3 ,-1 ,-0.7 ) (-1,-0.3,-0.5)