1function test8 2%TEST8 test cs_cholsol, cs_lusol 3% 4% Example: 5% test8 6% See also: testall 7 8% Copyright 2006-2012, Timothy A. Davis, http://www.suitesparse.com 9 10index = ssget ; 11[ignore f] = sort (max (index.nrows, index.ncols)) ; 12f = f (1:100) ; 13 14% f = f(1) 15 16for i = f 17 Prob = ssget (i) ; 18 disp (Prob) ; 19 A = Prob.A ; 20 [m n] = size (A) ; 21 if (~isreal (A) | m ~= n) %#ok 22 continue 23 end 24 25 spd = 0 ; 26 if (m == n) 27 if (nnz (A-A') == 0) 28 try 29 p = amd (A) ; 30 catch 31 p = symamd (A) ; 32 end 33 [R,p] = chol (A (p,p)) ; 34 spd = (p == 0) ; 35 end 36 end 37 38 if (spd) 39 C = A ; 40 else 41 C = A*A' + n*speye (n) ; 42 try 43 p = amd (C) ; 44 catch 45 p = symamd (C) ; 46 end 47 try 48 R = chol (C (p,p)) ; 49 catch 50 continue 51 end 52 end 53 54 b = rand (n,1) ; 55 56 x1 = C\b ; 57 x2 = cs_cholsol (C,b) ; 58 r1 = norm (C*x1-b,1) / norm (C,1) ; 59 r2 = norm (C*x2-b,1) / norm (C,1) ; 60 err = abs (r1-r2) ; 61 fprintf ('err %g\n', err) ; 62 if (err > 1e-10) 63 error ('!') ; 64 end 65 66 x2 = cs_lusol (C,b, 1, 0.001) ; 67 r2 = norm (C*x2-b,1) / norm (C,1) ; 68 err = abs (r1-r2) ; 69 fprintf ('err %g (lu with amd(A+A'')\n', err) ; 70 if (err > 1e-10) 71 error ('!') ; 72 end 73 74 if (m ~= n) 75 continue ; 76 end 77 78 x1 = A\b ; 79 r1 = norm (A*x1-b,1) / norm (A,1) ; 80 if (r1 < 1e-6) 81 x2 = cs_lusol (A,b) ; 82 r2 = norm (A*x2-b,1) / norm (A,1) ; 83 fprintf ('lu resid %g %g\n', r1, r2) ; 84 end 85end 86