scilab/modules/linear_algebra/tests/nonreg_tests/bug_9196.tst

   1 // =============================================================================
   2 // Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
   3 // Copyright (C) 2013 - Scilab Enterprises - Sylvestre Ledru
   4 // Copyright (C) 2013 - Michaël Baudin
   5 //
   6 //  This file is distributed under the same license as the Scilab package.
   7 // =============================================================================
   8
   9 // <-- CLI SHELL MODE -->
  10
  11 // <-- Non-regression test for bug 9196 -->
  12 //
  13 // <-- Bugzilla URL -->
  14 // http://bugzilla.scilab.org/show_bug.cgi?id=9196
  15 //
  16 // <-- Short Description -->
  17 //    The threshold level for conditioning in backslash is too small.
  18 // =============================================================================
  19
  20 n=9;
  21 A = testmatrix("hilb",n);
  22 b=ones(n,1);
  23 xexpected=[7129/2520
  24            4861/2520
  25            42131/27720
  26            35201/27720
  27            395243/360360
  28            348911/360360
  29            62575/72072
  30            113567/144144
  31            1768477/2450448];
  32 x=A\b;
  33 assert_checkalmostequal(x, xexpected);
  34
  35
  36 Ac=complex(A,zeros(A));
  37 bc=complex(b,zeros(b));
  38 xc = Ac\bc;
  39 xcexpected=complex(xexpected,zeros(xexpected));
  40 assert_checkalmostequal(xc, xexpected);
  41
  42 b=(1:n)';
  43 xexpected=[9;
  44            17819/2520;
  45            82609/13860;
  46            47959/9240;
  47            415567/90090;
  48            299737/72072;
  49            45533/12012;
  50            71761/20592;
  51            988277/306306];
  52 x=A\b;
  53 assert_checkalmostequal(x, xexpected);
  54 Ac=complex(A,zeros(A));
  55 bc=complex(b,zeros(b));
  56 xc = Ac\bc;
  57 xcexpected=complex(xexpected,zeros(xexpected));
  58 assert_checkalmostequal(xc, xexpected);
  59
  60 b=[1;-1;1;-1;1;-1;1;-1;1];
  61 xexpected=[1879/2520;
  62            893/2520;
  63            6557/27720;
  64            4993/27720;
  65            52901/360360;
  66            44911/360360;
  67            39173/360360;
  68            69659/720720;
  69            1068047/12252240];
  70 x=A\b;
  71 assert_checkalmostequal(x, xexpected);
  72 Ac=complex(A,zeros(A));
  73 bc=complex(b,zeros(b));
  74 xc = Ac\bc;
  75 xcexpected=complex(xexpected,zeros(xexpected));
  76 assert_checkalmostequal(xc, xexpected);