1function sqr_example 2%SQR_EXAMPLE test cs_sqr 3% Example: 4% sqr_example 5% See also: testall 6 7% Copyright 2006-2012, Timothy A. Davis, http://www.suitesparse.com 8 9Prob = ssget (706) ; 10 11A = Prob.A' ; 12q = colamd (A) ; 13A = A (:,q) ; 14A = sprandn (A) ; 15[m n] = size (A) ; 16 17[vnz, rnz, parent, c, leftmost, p] = cs_sqr(A) ; 18 19m2 = length (p) ; 20B = [A ; sparse(m2-m,n)] ; 21B = B (p,q) ; 22 23R1 = gqr3 (B) ; 24 25clf 26subplot (2,2,1) ; spy(A) 27subplot (2,2,3) ; spy (chol (A'*A + 100*speye(n))) ; 28subplot (2,2,4) ; spy (R1) ; 29