\(\newcommand{\W}[1]{ \; #1 \; }\) \(\newcommand{\R}[1]{ {\rm #1} }\) \(\newcommand{\B}[1]{ {\bf #1} }\) \(\newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} }\) \(\newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} }\) \(\newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} }\) \(\newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }\)
correct_det_by_minor_c¶
View page sourceCorrectness Test of det_by_minor Routine¶
Syntax¶
flag = correct_det_by_minor
()
flag¶
The return value has prototype
bool
flag
It value is 1
if the test passes and 0
otherwise.
Source Code¶
bool correct_det_by_minor(void)
{ double a[9], det, check;
double eps99 = 99.0 * DBL_EPSILON;
random_seed(123);
uniform_01(9, a);
/* compute determinant using expansion by minors */
det = det_by_minor(a, 3);
/* use expansion by minors to hand code the determinant */
check = 0.;
check += a[0] * ( a[4] * a[8] - a[5] * a[7] );
check -= a[1] * ( a[3] * a[8] - a[5] * a[6] );
check += a[2] * ( a[3] * a[7] - a[4] * a[6] );
if( fabs(det / check - 1.0) < eps99 )
return true;
return false;
}