26 integ_eval (
double ai,
double bi,
double ci,
double di,
double xi,
double a,
29 const double r1 =
a - xi;
30 const double r2 = b - xi;
31 const double r12 = r1 +
r2;
32 const double bterm = 0.5 * bi * r12;
33 const double cterm = (1.0 / 3.0) * ci * (r1 * r1 +
r2 *
r2 + r1 *
r2);
34 const double dterm = 0.25 * di * r12 * (r1 * r1 +
r2 *
r2);
36 return (b -
a) * (ai + bterm + cterm + dterm);
static double integ_eval(double ai, double bi, double ci, double di, double xi, double a, double b)