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