static double form_volume(double radius, double thickness) { return M_4PI_3 * cube(radius + thickness); } static double effective_radius(int mode, double radius, double thickness) { switch (mode) { default: case 1: // outer radius return radius + thickness; case 2: // core radius return radius; } } static void Fq(double q, double *F1, double *F2, double radius, double thickness, double core_sld, double shell_sld, double solvent_sld) { double form = core_shell_fq(q, radius, thickness, core_sld, shell_sld, solvent_sld); *F1 = 1.0e-2*form; *F2 = 1.0e-4*form*form; }