package DBC;

public abstract class Function {
	public abstract double [] derivative(double []a) throws Exception;
}

public class Exponential extends Function {

	@Override
	public double[] derivative(double[] a) throws Exception {
		if (a.length != 2 )
		{
			throw new Exception ("This is not an exponential");
		}
		for (int i = 0; i < a.length; i++) {
			if (Double.isNaN(a[i]) || Double.isInfinite(a[i]))
			{
				throw new Exception("Cant compute the derivative!");
			}
		}
		return new double[]{Math.log(a[0]), a[0], a[1]};
	}
}

public class Logarithmic extends Function {

	@Override
	public double[] derivative(double[] a) throws Exception {
		for (int i = 0; i < a.length; i++) {
			if (Double.isNaN(a[i]) || Double.isInfinite(a[i]))
			{
				throw new Exception ("Can't compute derivative");
			}
		}
		return new double[]{ 1 / ( a[1] * Math.log(a[0]))};
	}
}
public class Polynomial extends Function {
	@Override
	public double[] derivative(double[] a) throws Exception{

		int power = 1;
		for (int i = 0; i < a.length; i++) {
			if (Double.isNaN(a[i]) || Double.isInfinite(a[i]))
			{
				throw new Exception("Cant compute derivative");
			}
		}
		double [] result = new double[a.length - 1];
		for (int i = 0; i < result.length; i++)
		{
			result[i] = power * a[i + 1];
			power++;
		}

		return result;
	}

}

public class FunctionTest
{
	public static void main(String[] args)
	{
		double[] arrayPolynomial = new double[]{1, 2, 3, 4, 5};
		Polynomial polynomial = new Polynomial();
		try
		{
			double result[] = polynomial.derivative(arrayPolynomial);
			for (int i = 0; i < result.length; i++) {
				System.out.print(result[i] + " ");
			}
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}

		System.out.println();

		double[] arrayExponential = new double[]{3, 5};
		Exponential exp = new Exponential();
		try{
			double resultExp[] = exp.derivative(arrayExponential);
			for (int i = 0; i < resultExp.length; i++) {
				System.out.print(resultExp[i] + " ");
			}
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}

		System.out.println();

		double[]arrayLogarithmic = new double[]{2, 12};
		Logarithmic logarithmic = new Logarithmic();
		try{
			double []resultLog = logarithmic.derivative(arrayLogarithmic);
			for (int i = 0; i < resultLog.length; i++) {
				System.out.print(resultLog[i] + " ");
			}
		}
		catch(Exception e)
		{

		}
	}
}