SLIDE 8 METHODOLOGY - CA
Correspondence Analysis (CA)
Absolute frequencies matrix A A = (a i j) i=1,..,I; j=1,…,J
Relative frequencies matrix F F= (f i j) f i j = a i j /a a = i j a i j
Column profile {f i j/ f. j , i =1,.. I }
Distance between column profiles j , j’ d2 (j , j’)
d2 (j, j’) = 1/f i. (f i j / f .j - f i j’ /f .j’) 2
Calculation of eigenvalues and eigenvectors of X’X , X = (xi j)
x i j = √ fi. (f i j / f i. f .j – 1) √ f .j
*Juxtaposed Tables
Absolute frequencies matrix A A = (a i j k ) i=1,..,I; j=1,…,J k, k=1,...K
Relative frequencies matrix F F= (f i j k) f i j k = a i j k / a a = i j k a i j k
Simultaneous Analysis (SA)
Absolute frequencies matrix A A = (a i j k ) i=1,..,I; j=1,…,J k, k=1,...K
Relative frequencies matrix F F= (f i j k) f i j k = a i j k / a ..k a ..k = i j a i j k