// Huen's Method for ODEs that return a double
double heuns_3dF2d(double x_k, double y_k, double x_step, double (*differential)(double, double)){
double k1, k2, half_step;
half_step = x_step / 2.0;
k1 = differential(x_k, y_k);
k2 = differential( (x_k + x_step), (y_k + (x_step * k1)) );
return ( y_k + half_step * (k1+k2) );
}
static gint
edge_detect (const guchar *data)
{
gint ret;
switch (evals.edgemode)
{
case SOBEL:
ret = sobel (data);
break;
case PREWITT:
ret = prewitt (data);
break;
case GRADIENT:
ret = gradient (data);
break;
case ROBERTS:
ret = roberts (data);
break;
case DIFFERENTIAL:
ret = differential (data);
break;
case LAPLACE:
ret = laplace (data);
break;
default:
ret = -1;
break;
}
return CLAMP0255 (ret);
}
Real
AuxChem::computeValue()
{
Real matrix_energy(0.0);
Real precip_energy(0.0);
Real differential(0.0);
matrix_energy = computeEnergy(_coupled_cons[_qp], _coupled_noncons[_qp], true);
precip_energy = computeEnergy(_precip_conserved, _precip_nonconserved, false);
differential = computeDifferential(_coupled_cons[_qp], _coupled_noncons[_qp]);
return (matrix_energy - precip_energy + differential);
}
int main() {
double h = 0;
double x = 0;
x = 1.8;
/* 0.1 */
h = 0.1;
printf("h = %2.5lf, f(%2.5lf + %2.5lf) = %10.5lf, f' = %10.5lf\n",
h, x, h, log(x + h), differential(log, h, x));
/* 0.01 */
h = 0.01;
printf("h = %2.5lf, f(%2.5lf + %2.5lf) = %10.5lf, f' = %10.5lf\n",
h, x, h, log(x + h), differential(log, h, x));
/* 0.001 */
h = 0.001;
printf("h = %2.5lf, f(%2.5lf + %2.5lf) = %10.5lf, f' = %10.5lf\n",
h, x, h, log(x + h), differential(log, h, x));
return 0;
}
