1function test15 2%TEST15 test cs_amd 3% 4% Example: 5% test15 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 14for trials = 1:100 15 n = fix (200 * rand (1)) ; 16 d = 0.05 * rand (1) ; 17 A = sprandn (n, n, d) ; 18 19 % add a randomly placed dense column 20 k = fix (n * rand (1)) ; 21 k = max (1, k) ; 22 k = min (n, k) ; 23 if (n > 0) 24 A (:,k) = 1 ; 25 end 26 27 if (~ispc) 28 if (rand ( ) > .5) 29 A = A + 1i * sprand (A) ; 30 end 31 end 32 33 try 34 p0 = amd (A) ; 35 catch 36 p0 = symamd (A) ; 37 end 38 p1 = cs_amd (A) ; 39 40 if (any (sort (p1) ~= 1:n)) 41 error ('not perm!') ; 42 end 43 44 C = A+A' + speye (n) ; 45 lnz0 = sum (symbfact (C (p0,p0))) ; 46 lnz1 = sum (symbfact (C (p1,p1))) ; 47 subplot (1,3,1) ; spy (C) 48 subplot (1,3,2) ; spy (C (p0,p0)) 49 subplot (1,3,3) ; spy (C (p1,p1)) 50 fprintf ('n %4d nz %6d lnz %6d %6d\n', n, nnz(A), lnz0, lnz1) ; 51 drawnow 52 53end 54 55