package sansmodels;

public class OblateCoreShell extends SANSModel{
 
    private double scale, majorCoreAxis, majorShellAxis, background;
    private double minorShellAxis, minorCoreAxis, coreShellContrast;
    private double shellSolventContrast;

    //Default constructor
    public OblateCoreShell() {
        scale = 1.0;
        majorCoreAxis = 200.0;
        minorCoreAxis = 20.0;
        majorShellAxis = 250.0;
        minorShellAxis = 30.0;
        coreShellContrast = 1.e-6;
        shellSolventContrast = 1.e-6;
        background = 0.00;
        setNumberOfParameters(8);
        String[] parameters = {"Scale", "Core Major Axis (A)",
            "Core Minor Axis (A)", "Shell Major Axis (A)",
            "Shell Minor Axis (A)", "Core-Shell Cont(A-2)",
            "Shell-Solv Cont(A-2)", "Background (cm-1)"};
        setParametersText(parameters);
    }

    public OblateCoreShell(double inScale, 
                     double inMajorCoreAxis,
                     double inMinorCoreAxis,
                     double inMajorShellAxis,
                     double inMinorShellAxis,
                     double inCoreShellContrast,
                     double inShellSolventContrast,
                     double inBackground) {
        scale = inScale; 
        majorCoreAxis = inMajorCoreAxis;
        minorCoreAxis = inMinorCoreAxis;
        majorShellAxis = inMajorShellAxis;
        minorShellAxis = inMinorShellAxis;
        coreShellContrast = inCoreShellContrast;
        shellSolventContrast = inShellSolventContrast;
        background = inBackground;
        setNumberOfParameters(8);
        String[] parameters = {"Scale", "Core Major Axis (A)",
            "Core Minor Axis (A)", "Shell Major Axis (A)",
            "Shell Minor Axis (A)", "Core-Shell Contrast (A-2)",
            "Shell-Solvent Contrast (A-2)", "Background (cm-1)"};
        setParametersText(parameters);
    }

    private double oblateCoreShellFunc(double inQ, double inZ) {
       double pi43,aa,bb,u2,ut2,u,ut,vc,vt,gfnc,gfnt,tgfn,cc,dd;
       
       pi43 = 4.0/3.0*Math.PI;
       aa = majorCoreAxis;
       bb = minorCoreAxis;
       cc = majorShellAxis;
       dd = minorShellAxis;
       u2 = (bb*bb*inZ*inZ + aa*aa*(1.0-inZ*inZ));
       ut2 = (dd*dd*inZ*inZ + cc*cc*(1.0-inZ*inZ));
       u = Math.sqrt(u2)*inQ;
       ut = Math.sqrt(ut2)*inQ;
       vc = pi43*aa*aa*bb;
       vt = pi43*cc*cc*dd;
       gfnc = 3.0*(Math.sin(u)/u/u - Math.cos(u)/u)/u*vc*coreShellContrast;
       gfnt = 3.0*(Math.sin(ut)/ut/ut - Math.cos(ut)/ut)/ut
              *vt*shellSolventContrast;
       tgfn = gfnc+gfnt;
       
       return tgfn*tgfn; 
    }

    public double getFormFactor(double inX) {
        double nord, va, vb, zi, yyy, summ, answer, vol;
        nord = 76;
        va = 0.0;
        vb = 1.0;
        
        summ = 0.0;
        for(int i=0;i<nord;i++) {
            zi = (Gaussian.z76[i]*(vb-va) + vb + va)/2.0;
            yyy = Gaussian.w76[i]*oblateCoreShellFunc(inX,zi);
            summ += yyy;
        }

        answer = (vb-va)/2.0*summ;
 
        vol = 4*Math.PI/3.0*majorShellAxis*majorShellAxis*minorShellAxis;
        return answer/vol*1.0e8*scale*getStructureFactor().calculate(inX)
            + background;
    }

    public void setParameters(double[] inParameters) {
        scale = inParameters[0];
        majorCoreAxis = inParameters[1];
        minorCoreAxis = inParameters[2];
        majorShellAxis = inParameters[3];
        minorShellAxis = inParameters[4];
        coreShellContrast = inParameters[5];
        shellSolventContrast = inParameters[6];
        background = inParameters[7];
    }
 
    public double[] getParameters() {
        double[] outParameters = new double[8];
        outParameters[0] = scale;
        outParameters[1] = majorCoreAxis;
        outParameters[2] = minorCoreAxis;
        outParameters[3] = majorShellAxis;
        outParameters[4] = minorShellAxis;
        outParameters[5] = coreShellContrast;
        outParameters[6] = shellSolventContrast;
        outParameters[7] = background;
        return outParameters;
    }
}