package Tutorial7;

public class Integration
{
    // Regla rectangular
    public static double rectangular(MathFunction f, double a, double b, int nPanels)
    {
        double answer = 0;
        double h = (b-a)/nPanels;
        double x=a;
        for(int i=1; i<=nPanels; i++)
        {
            answer = answer + f.func(x);
            x = a+i*h;
        }
        return(h*answer);
    }
    
    // Regla trapezoidal
    public static double trapezoidal(MathFunction f, double a, double b, int nPanels)
    {
        double answer = 0;
        double h = (b-a)/nPanels;
        double x=a;
        for(int i=1; i<=nPanels; i++)
        {
            answer += 0.5* (f.func(x)+f.func(x+h));
            x= a+i*h;
        }
        return(h*answer);
    }
    
    // Regla de Simpson
    public static double simpson(MathFunction f, double a, double b, int nPanels)
    {
        double answer=0;
        double x=a;
        double h = (b-a)/nPanels;
        for(int i=1; i<=nPanels; i++)
        {
            answer += (f.func(x)+4*f.func(x+h/2) + f.func(x+h))/6;
            x = a+i*h;
        }
        return(h*answer);
    }
    
}