/*
 * Created on Mar 9, 2005
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package test;

/**
 * @author vijay_dharap
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class RateTest {

	public static void main(String[] args) {
		RateTest rt = new RateTest();
		double rate = rt.rate(36, -38035, 4894.9333, 21252, 12, 12, 0, 1);
		System.out.println(rate);
	}

	/*************************************************/
	/** The Rate Function and related functions      */
	/*************************************************/
		/**
		 *  ratio used in iterative solution for interest
		 */
		private double ratio = 1e4;

		/**
		 * Method _fi_calc_interest. Method to calculate the interest rate depending on all the params
		 * @param per  number of periods
		 * @param pv  present value
		 * @param pmt periodic payment
		 * @param fv future value
		 * @param CF compounding frequency
		 * @param PF payment frequency
		 * @param disc discrete/continuous compounding
		 * @param bep beginning/end of period payment
		 * @return double
		 */
		private double rate(int per,/* number of periods */
			double pv, /* present value */
			double pmt, /* periodic payment */
			double fv, /* future value */
			int CF, /* compounding frequency */
			int PF, /* payment frequency */
			int disc, /* discrete/continuous compounding */
			int bep) /* beginning/end of period payment */
		{
			double eint;
			double a, dik;
			int ri;

			if (pmt == 0.0)
				eint = Math
						.pow((Math.abs(fv) / Math.abs(pv)), (1.0 / (double) per)) - 1.0;
			else {
				if ((pmt * fv) < 0.0) {
					if (pv != 0)
						a = -1.0;
					else
						a = 1.0;
					eint = Math.abs((fv + a * (double) per * pmt)
							/ (3.0 * (((double) per - 1.0) * ((double) per - 1.0)
									* pmt + pv - fv)));
				} else {
					if ((pv * pmt) < 0.0) {
						eint = Math.abs(((double) per * pmt + pv + fv)
								/ ((double) per * pv));
					} else {
						a = Math.abs(pmt / (Math.abs(pv) + Math.abs(fv)));
						eint = a + 1.0
								/ (a * (double) per * (double) per * (double) per);
					}
				}
				do {
					dik = fi(per, eint, pv, pmt, fv, bep)
							/ fip(per, eint, pv, pmt, fv, bep);
					eint -= dik;
					ri = (int) Math.floor(ratio * (dik / eint));
				} while (ri != 0);
			} /* endif */

			return eint ;
			// i need only eint and not nom_int
			// so commented
//			return 100.0 * nom_int(eint, CF, PF, disc);
		} /* _fi_calc_interest */

//		/* compute Nominal Interest Rate from Effective Interest Rate */
//		private double nom_int(double eint, int CF, int PF, int disc) {
//			double nint;
	//
//			if (disc != 0) {
//				if (CF == PF) {
//					nint = CF * eint;
//				} else {
//					nint = CF
//							* (Math.pow((1.0 + eint), ((double) PF / (double) CF)) - 1.0);
//				} /* * endif */
//			} else
//				nint = Math.log(Math.pow(1.0 + eint, PF));
	//
//			return nint;
//		} /* nom_int */

		/* calculation used in interest computation */
		private double fi(int per, double eint, double pv, double pmt, double fv,
				int bep) {
			return interestCalc1(eint, per) * (pv + interestCalc3(eint, pmt, bep)) + pv + fv;
		} /* fi */

		/*
		 * calculation used in interest computation
		 */
		private double fip(int per, double eint, double pv, double pmt, double fv,
				int bep) {
			double AA = interestCalc1(eint, per);
			double CC = interestCalc3(eint, pmt, bep);
			double D = (AA + 1.0) / (1.0 + eint);

			return (double) per * (pv + CC) * D - (AA * CC) / eint;
		} /* fip */

		/* Compute constant used in calculations */
		private double interestCalc1(double eint, int per) {
			return Math.pow((1.0 + eint), (double) per) - 1.0;
		} /* interestCalc1 */

		/* Compute constant used in calculations */
		private double interestCalc2(double eint, int beg) {
			/* the following should call an error routine to report the error */
			if (eint == 0.0) {
				System.err.println("Zero Interest.!!\n");
				System.exit(1);
			} /* endif */

			return (1.0 + eint * (double) beg) / eint;
		} /* interestCalc2 */

		/* Compute constant used in calculations */
		private double interestCalc3(double eint, double pmt, int beg) {
			return pmt * interestCalc2(eint, beg);
		} /* interestCalc3 */

	/****************************************************/
	/** end of The Rate Function and related functions  */
	/****************************************************/

}