▁The ▁next ▁canonical ▁functions , ▁U 2 ▁and ▁V 2 ▁are ▁then ▁restricted ▁so ▁that ▁they ▁are ▁un cor related ▁with ▁U 1 ▁and ▁V 1 . ▁Everything ▁is ▁scale d ▁so ▁that ▁the ▁variance ▁equals   1 . ▁ ▁One ▁can ▁also ▁construct ▁relationships ▁which ▁are ▁made ▁to ▁agree ▁with ▁constraint ▁restrictions ▁ar ising ▁from ▁theory ▁or ▁to ▁agree ▁with ▁common ▁sense / int u ition . ▁These ▁are ▁called ▁maximum ▁correlation ▁models . ▁( T of all is , ▁ 1 9 9 9 ) ▁ ▁Mathemat ically , ▁canonical ▁analysis ▁maxim izes ▁U ′ X ′ Y V ▁subject ▁to ▁U ′ X ′ X U   =   I ▁and ▁V ′ Y ′ Y V   =   I , ▁where ▁X ▁and ▁Y ▁are ▁the ▁data ▁matrices ▁( row ▁for ▁instance ▁and ▁column ▁for ▁feature ). ▁ ▁See ▁also ▁ ▁R V ▁coefficient ▁ ▁References ▁▁ ▁Category : Reg ression ▁analysis <0x0A> </s> ▁Angel osa urus ▁ ▁(' Ang el ▁l izard ', ▁Ol son ▁& ▁Ber rb ower ▁ 1 9 5 3 ) ▁was ▁a ▁p ely c osa ur ▁( an ▁ext inct ▁cla de ) ▁of ▁re pt ile . ▁The ▁type ▁species , ▁Angel osa urus ▁dol ani ▁is ▁known ▁from ▁a ▁partial ▁sk ull ▁from ▁the ▁Middle ▁San ▁Ang elo ▁Form ation , ▁Kno x ▁County , ▁Texas , ▁USA ▁d ating ▁from ▁the ▁K ung ur ian ▁( E ar ly ▁Perm ian ). ▁The ▁spec imen ▁represented ▁an ▁individual