source: sasview/sansmodels/src/sans/models/c_extensions/triaxial_ellipsoid.h @ 72a90bd

#if !defined(triaxial_ellipsoid_h)
#define triaxial_ellipsoid_h
/** Structure definition for cylinder parameters
 * [PYTHONCLASS] = TriaxialEllipsoidModel
 * [DISP_PARAMS] = axis_theta, axis_phi
   [DESCRIPTION] = <text> Note:
                                        Constraints must be applied during fitting to ensure that the inequality a<b<c is not
                                                  violated. The calculation will not report an error, but the results will not be correct.
                                   </text>
        [FIXED]= <text>axis_phi.width; axis_theta.width; semi_axisA.width; semi_axisB.width; semi_axisC.width </text>
        [ORIENTATION_PARAMS]= <text>axis_phi; axis_theta; axis_phi.width; axis_theta.width</text>


 **/
typedef struct {
    /// Scale factor
    //  [DEFAULT]=scale=1.0
    double scale;
    /// semi -axis B of the triaxial_ellipsoid [A]
    //  [DEFAULT]=semi_axisB= 35.0 [A]
    double semi_axisA;
    /// semi -axis B of the triaxial_ellipsoid [A]
    //  [DEFAULT]=semi_axisA=100.0 [A]
    double semi_axisB;
        /// semi -axis C of the triaxial_ellipsoid [A]
    //  [DEFAULT]=semi_axisC=400.0 [A]
    double semi_axisC;
    /// Contrast [1/A²]
    //  [DEFAULT]=contrast=5.3e-6 [1/A²]
    double contrast;
        /// Incoherent Background [1/cm] 0.00
        //  [DEFAULT]=background=0.0 [1/cm]
        double background;
    /// Orientation of the triaxial_ellipsoid axis w/respect incoming beam [rad]
    //  [DEFAULT]=axis_theta=1.0 [rad]
    double axis_theta;
    /// Orientation of the triaxial_ellipsoid in the plane of the detector [rad]
    //  [DEFAULT]=axis_phi=1.0 [rad]
    double axis_phi;

} TriaxialEllipsoidParameters;



/// 1D scattering function
double triaxial_ellipsoid_analytical_1D(TriaxialEllipsoidParameters *pars, double q);

/// 2D scattering function
double triaxial_ellipsoid_analytical_2D(TriaxialEllipsoidParameters *pars, double q, double phi);
double triaxial_ellipsoid_analytical_2DXY(TriaxialEllipsoidParameters *pars, double qx, double qy);
double triaxial_ellipsoid_analytical_2D_scaled(TriaxialEllipsoidParameters *pars, double q, double q_x, double q_y);

#endif