1function test16
2%TEST16 test cs_amd
3%
4% Example:
5%   test16
6% See also: testall
7
8% Copyright 2006-2012, Timothy A. Davis, http://www.suitesparse.com
9
10rand ('state', 0) ;
11randn ('state', 0) ;
12clf
13
14index = ssget ;
15[ignore f] = sort (max (index.nrows, index.ncols)) ;
16f = f (1:200) ;
17skip = 811 ;
18
19% f = 719
20
21for i = f
22    if (any (i == skip))
23        continue
24    end
25    Prob = ssget (i) ;
26    A = spones (Prob.A) ;
27    Aorig = A ;
28    [m n] = size (A) ;
29    if (m < n)
30        A = A' ;
31    end
32    [m n] = size (A) ;
33    if (m ~= n)
34        A = A'*A ;
35    end
36
37    if (~ispc)
38        if (rand ( ) > .5)
39            A = A + 1i * sprand (A) ;
40        end
41    end
42
43    fprintf ('n %4d nz %d\n', n, nnz (A)) ;
44
45    try
46        p0 = amd (A) ;
47    catch
48        p0 = symamd (A) ;
49    end
50    fprintf ('symmetric case:\n') ;
51    p1 = cs_amd (A) ;
52
53    if (any (sort (p1) ~= 1:n))
54        error ('not perm!') ;
55    end
56
57    C = A+A' + speye (n) ;
58    lnz0 = sum (symbfact (C (p0,p0))) ;
59    lnz1 = sum (symbfact (C (p1,p1))) ;
60    subplot (2,3,1) ; spy (C)
61    subplot (2,3,2) ; spy (C (p0,p0)) ; title ('amd') ;
62    subplot (2,3,3) ; spy (C (p1,p1)) ; title ('csamd') ;
63    drawnow
64
65    if (lnz0 ~= lnz1)
66        fprintf ('----------------- lnz %d %d   %9.4f\n', ...
67            lnz0, lnz1, 100*(lnz0-lnz1)/max([1 lnz0])) ;
68    end
69
70    if (1)
71
72        p0 = colamd (Aorig) ;
73        [m n] = size (Aorig) ;
74        fprintf ('m %d n %d\n', m, n) ;
75
76        fprintf ('A''A case, no dense rows (for QR):\n') ;
77        p1 = cs_amd (Aorig, 3) ;
78        if (any (sort (p1) ~= 1:n))
79            error ('not perm!') ;
80        end
81
82        subplot (2,3,4) ; spy (Aorig)
83        subplot (2,3,5) ; spy (Aorig (:,p0)) ; title ('colamd') ;
84        subplot (2,3,6) ; spy (Aorig (:,p1)) ; title ('cs amd(A''A)') ;
85        lnz0 = sum (symbfact (Aorig (:,p0), 'col')) ;
86        lnz1 = sum (symbfact (Aorig (:,p1), 'col')) ;
87        fprintf ('                    A''A: %7d %7d %9.4f\n', ...
88            lnz0, lnz1, 100*(lnz0-lnz1)/max([1 lnz0])) ;
89        drawnow
90
91        % pause
92
93    end
94end
95
96