package sansmodels;

public class CoreShell extends SANSModel{
 
    private double scale, coreRadius, thickness, background;
    private double rhoCore, rhoShell, rhoSolvent;

    //Default constructor
    public CoreShell() {
        scale = 1.0;
        coreRadius = 60.0;
        thickness = 10.0;
        rhoCore = 1.e-6;
        rhoShell = 2.e-6;
        rhoSolvent = 3.e-6;
        background = 0.00;
        setNumberOfParameters(7);
        String[] parameters = {"Scale", "Core Radius (A)", 
            "Shell Thickness (A)", "Core SLD (A-2)", "Shell SLD (A-2)",
            "Solvent SLD (A-2)", "Background (cm-1)"};
        setParametersText(parameters);
    }

    public CoreShell(double inScale, 
                     double inCoreRadius,
                     double inThickness,
                     double inRhoCore,
                     double inRhoShell,
                     double inRhoSolvent,
                     double inBackground) {
        scale = inScale; 
        coreRadius = inCoreRadius;
        thickness = inThickness;
        rhoCore = inRhoCore;
        rhoShell = inRhoShell;
        rhoSolvent = inRhoSolvent;
        background = inBackground;
        setNumberOfParameters(7);
        String[] parameters = {"Scale", "Core Radius (A)", 
            "Shell Thickness (A)", "Core SLD (A-2)", "Shell SLD (A-2)",
            "Solvent SLD (A-2)", "Background (cm-1)"};
        setParametersText(parameters);
    }

    public double getFormFactor(double inX) {
        double bes, f, vol, f2,qr,contr;

        //Core first
        qr = inX*coreRadius;
        contr = rhoCore - rhoShell;
        bes = 3.*(Math.sin(qr) - qr*Math.cos(qr))/ Math.pow(qr,3.0);
        vol = 4.0*Math.PI/3.0*Math.pow(coreRadius,3.0);
        f = vol*bes*contr;
        
        //Then Shell
        qr = inX*(coreRadius+thickness);
        contr = rhoShell - rhoSolvent;
        bes = 3.*(Math.sin(qr) - qr*Math.cos(qr))/ Math.pow(qr,3.0);
        vol = 4.0*Math.PI/3.0*Math.pow(coreRadius+thickness,3.0);
        f += vol*bes*contr;
        
        f2 = f*f/vol*1.0e8;
        return scale*f2*getStructureFactor().calculate(inX) + background;
    }


    public void setParameters(double[] inParameters) {
        scale = inParameters[0];
        coreRadius = inParameters[1];
        thickness = inParameters[2];
        rhoCore = inParameters[3];
        rhoShell = inParameters[4];
        rhoSolvent = inParameters[5];
        background = inParameters[6];
    }

    public double[] getParameters() {
        double[] outParameters = new double[7];
        outParameters[0] = scale;
        outParameters[1] = coreRadius;
        outParameters[2] = thickness;
        outParameters[3] = rhoCore;
        outParameters[4] = rhoShell;
        outParameters[5] = rhoSolvent;
        outParameters[6] = background;
        return outParameters;
    }

}