rendered paste bodyimport java.io.IOException;import java.util.Scanner;import org.apfloat.ApfloatMath;import org.apfloat.Apfloat;/* * To change this template, choose Tools | Templates * and open the template in the editor. *//** * * @author Jake Gunter */public class PiSalaminBrent { private long precision = 1000; private Apfloat[] calculateNums(Apfloat[] lastIter, int iter, int desiredIter) { Apfloat[] toReturn = new Apfloat[4]; toReturn[0] = (lastIter[0].add(lastIter[1])).divide(new Apfloat(2)); toReturn[1] = ApfloatMath.sqrt(lastIter[0].multiply(lastIter[1])); Apfloat x = ApfloatMath.pow((lastIter[0].subtract(toReturn[0])), 2); toReturn[2] = lastIter[2].subtract(lastIter[3].multiply(x)); toReturn[3] = lastIter[3].multiply(new Apfloat(2)); if (iter == desiredIter) return toReturn; return calculateNums(toReturn, ++iter, desiredIter); } private Apfloat calculate2(Apfloat a, int iter, int desiredIter) { a = a.subtract(ApfloatMath.tan(a)); if (iter == desiredIter) return a; return calculate2(a, iter+1, desiredIter); } private Apfloat calculateNonic(Apfloat a, int iter, int desiredIter) { Apfloat firstTerm = ApfloatMath.tan(a); Apfloat secondTerm = (new Apfloat(1, precision).divide(new Apfloat(3, precision))).multiply(ApfloatMath.pow(ApfloatMath.tan(a), 3)); Apfloat thirdTerm = (new Apfloat(1, precision).divide(new Apfloat(5, precision))).multiply(ApfloatMath.pow(ApfloatMath.tan(a), 5)); Apfloat fourthTerm = (new Apfloat(1, precision).divide(new Apfloat(7, precision))).multiply(ApfloatMath.pow(ApfloatMath.tan(a), 7)); return ApfloatMath.sum(a, firstTerm.negate(), secondTerm, thirdTerm.negate(), fourthTerm); } private Apfloat calculateVeryVerySimplest(long precision) { return new Apfloat(4, precision).multiply(ApfloatMath.atan(new Apfloat(1, precision))); } private Apfloat calculateSimplest(Apfloat curIter, int iter, int desiredIter) { Apfloat toReturn = curIter.add(ApfloatMath.sin(curIter)); if (iter == desiredIter) return toReturn; return calculateSimplest(toReturn, ++iter, desiredIter); } private Apfloat calculateSimpler(long precision) { Apfloat a = Apfloat.ONE.divide(ApfloatMath.sqrt(new Apfloat(3, precision))); a = ApfloatMath.atan(a); return a.multiply(new Apfloat(6, precision)); } private Apfloat calculateMachinLikeSimple(long precision) { Apfloat oneFifth = Apfloat.ONE.divide(new Apfloat(5, precision)); Apfloat oneTwoThirtyNinth = Apfloat.ONE.divide(new Apfloat(239, precision)); Apfloat pi = (new Apfloat(4, precision).multiply(ApfloatMath.atan(oneFifth))).subtract(ApfloatMath.atan(oneTwoThirtyNinth)); return pi.multiply(new Apfloat(4, precision)); } public static void main(String[] args) throws IOException { long precision = 10000; Scanner in = new Scanner(System.in); do { System.out.println("\nPI CALCULATOR, V. 3.0"); System.out.println("----------------------------------"); System.out.print("How many digits? Type in a number less than 1 to exit. "); precision = in.nextLong(); /* Apfloat a = Apfloat.ZERO; Apfloat b = Apfloat.ONE.divide(ApfloatMath.sqrt(new Apfloat(2))); Apfloat c = new Apfloat(.25); Apfloat d = Apfloat.ONE; Apfloat[] pi = new PiSalaminBrent().calculateNums(new Apfloat[] {a, b, c, d}, 0, 3); Apfloat num = ApfloatMath.pow(pi[0].add(pi[1]), 2); Apfloat den = new Apfloat(4).multiply(pi[3]); System.out.println((num.divide(den)).toString(true));*/ if (precision > 0) { long start = System.currentTimeMillis(); Apfloat pi = new PiSalaminBrent().//calculateSimplest(new Apfloat(22, precision).divide(new Apfloat(7, precision)), 0, 2); //calculateSimpler(precision); //calculate2(new Apfloat(22, precision).divide(new Apfloat(7, precision)), 0, 10); //calculateVeryVerySimplest(precision); calculateMachinLikeSimple(precision); long total = System.currentTimeMillis() - start; System.out.println(pi.toString(true)); System.out.println("Calculation took " + total + " milliseconds."); } } while (precision > 0); }}