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mXparser is a super easy, rich, fast and highly flexible math expression parser library (parser and evaluator of mathematical expressions / formulas provided as plain text / string). Software delivers easy to use API for JAVA, Android and C# .NET/MONO (Common Language Specification compliant: F#, Visual Basic, C++/CLI). *** If you find the software useful donation or purchase is something you might consider: https://mathparser.org/donate/ *** Online store: https://payhip.com/INFIMA *** Scalar Scientific Calculator, Charts and Scripts, Scalar Lite: https://play.google.com/store/apps/details?id=org.mathparser.scalar.lite *** Scalar Pro: https://play.google.com/store/apps/details?id=org.mathparser.scalar.pro *** ScalarMath.org: https://scalarmath.org/ *** MathSpace.pl: https://mathspace.pl/ ***

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/*
 * @(#)MathFunctions.java        6.0.0    2024-05-19
 *
 * MathParser.org-mXparser DUAL LICENSE AGREEMENT as of date 2024-05-19
 * The most up-to-date license is available at the below link:
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package org.mariuszgromada.math.mxparser.mathcollection;

import java.math.BigDecimal;
import java.math.MathContext;
import java.math.RoundingMode;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.util.Locale;

import org.mariuszgromada.math.mxparser.Argument;
import org.mariuszgromada.math.mxparser.Expression;
import org.mariuszgromada.math.mxparser.mXparser;

/**
 * MathFunctions - the most popular math functions. Many of function implemented by this class
 * could be found in java Math package (in fact functions from MathFunctions typically calls
 * original functions from the Math package). The reason why it was "re-implemented" is:
 * if you decide to implement your own function you do not need to change anything in the parser,
 * jut modify function implementation in this class.
 *
 * @author         Mariusz Gromada
* MathParser.org - mXparser project page
* mXparser on GitHub
* INFIMA place to purchase a commercial MathParser.org-mXparser software license
* [email protected]
* ScalarMath.org - a powerful math engine and math scripting language
* Scalar Lite
* Scalar Pro
* MathSpace.pl
* * @version 5.2.0 */ public final class MathFunctions { private static int MAX_RECURSION_CALLS = mXparser.getMaxAllowedRecursionDepth(); private static final DecimalFormat DECIMAL_FORMAT = new DecimalFormat("0", DecimalFormatSymbols.getInstance(Locale.ENGLISH)) {{setMaximumFractionDigits(340);}}; private static void refreshMaxAllowedRecursionDepth() { MAX_RECURSION_CALLS = mXparser.getMaxAllowedRecursionDepth(); } /** * Addition a + b applying canonical rounding if canonical * rounding is enabled * * @param a The a parameter * @param b The b parameter * @return The result of addition */ public static double plus(double a, double b) { if (Double.isNaN(a)) return Double.NaN; if (Double.isNaN(b)) return Double.NaN; if (!mXparser.checkIfCanonicalRounding()) return a + b; if (Double.isInfinite(a)) return a + b; if (Double.isInfinite(b)) return a + b; BigDecimal da = BigDecimal.valueOf(a); BigDecimal db = BigDecimal.valueOf(b); return da.add(db).doubleValue(); } /** * Subtraction a - b applying canonical rounding if canonical * rounding is enabled * * @param a The a parameter * @param b The b parameter * @return The result of subtraction */ public static double minus(double a, double b) { if (Double.isNaN(a)) return Double.NaN; if (Double.isNaN(b)) return Double.NaN; if (!mXparser.checkIfCanonicalRounding()) return a - b; if (Double.isInfinite(a)) return a - b; if (Double.isInfinite(b)) return a - b; BigDecimal da = BigDecimal.valueOf(a); BigDecimal db = BigDecimal.valueOf(b); return da.subtract(db).doubleValue(); } /** * Multiplication a * b applying canonical rounding if canonical * rounding is enabled * * @param a The a parameter * @param b The b parameter * @return The result of multiplication */ public static double multiply(double a, double b) { if (Double.isNaN(a)) return Double.NaN; if (Double.isNaN(b)) return Double.NaN; if (!mXparser.checkIfCanonicalRounding()) return a * b; if (Double.isInfinite(a)) return a * b; if (Double.isInfinite(b)) return a * b; BigDecimal da = BigDecimal.valueOf(a); BigDecimal db = BigDecimal.valueOf(b); return da.multiply(db).doubleValue(); } /** * Division a / b applying canonical rounding if canonical * rounding is enabled * * @param a The a parameter * @param b The b parameter * @return The result of division */ public static double div(double a, double b) { if (b == 0) return Double.NaN; if (Double.isNaN(a)) return Double.NaN; if (Double.isNaN(b)) return Double.NaN; if (!mXparser.checkIfCanonicalRounding()) return a / b; if (Double.isInfinite(a)) return a / b; if (Double.isInfinite(b)) return a / b; BigDecimal da = BigDecimal.valueOf(a); BigDecimal db = BigDecimal.valueOf(b); try { return da.divide(db, MathContext.DECIMAL128).doubleValue(); } catch (Throwable e) { return a / b; } } /** * Integer division (also called quotient) a / b applying canonical rounding if canonical * rounding is enabled * * @param a The a parameter * @param b The b parameter * @return The result of integer division */ public static double divQuotient(double a, double b) { double result = div(a, b); if (Double.isNaN(result) || Double.isInfinite(result)) return result; if (isAlmostInt(result)) return Math.round(result); return Math.floor(result); } /** * Bell Numbers * * @param n the n * * @return if n >= 0 returns Bell numbers, * otherwise returns Double.NaN. */ public static double bellNumber(int n) { double result = Double.NaN; if (n > 1) { n -= 1; if ( (n+1)*(n+1) >= Integer.MAX_VALUE ) return Double.NaN; long[][] bellTriangle = new long[n+1][n+1]; bellTriangle[0][0] = 1; bellTriangle[1][0] = 1; for (int r = 1; r <= n; r++) { for (int k = 0; k < r; k++) bellTriangle[r][k+1] = bellTriangle[r-1][k] + bellTriangle[r][k]; if (r < n) bellTriangle[r+1][0] = bellTriangle[r][r]; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } result = bellTriangle[n][n]; } else if (n >= 0) result = 1; return result; } /** * Bell number * @param n the n * * @return if n <> Double.NaN return bellNumber( (int)Math.round(n) ), * otherwise return Double.NaN. */ public static double bellNumber(double n) { if (Double.isNaN(n)) return Double.NaN; return bellNumber( (int)Math.round(n) ); } /** * Euler numbers * * @param n the n function param * @param k the k function param * * @return if n >=0 returns Euler number, * otherwise return Double.NaN. * Returns also Double.NaN when MAX RECURSION CALLS * is exceeded. * * @see mXparser#getMaxAllowedRecursionDepth() * @see mXparser#setMaxAllowedRecursionDepth(int) */ public static double eulerNumber(int n, int k) { refreshMaxAllowedRecursionDepth(); return eulerNumber(n, k, 1); } private static double eulerNumber(int n, int k, int recursionCall) { if (recursionCall > MAX_RECURSION_CALLS) return Double.NaN; if (n < 0) return Double.NaN; if (k < 0) return 0; if (n == 0) if (k == 0) return 1; else return 0; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; double e1 = eulerNumber(n - 1, k, recursionCall+1); if (Double.isNaN(e1)) return Double.NaN; double e2 = eulerNumber(n - 1, k - 1, recursionCall + 1); if (Double.isNaN(e2)) return Double.NaN; return (k + 1) * e1 + (n - k) * e2; } /** * Euler numbers * * @param n the n function param * @param k the k function param * * @return if n, k <> Double.NaN returns eulerNumber( (int)Math.round(n), (int)Math.round(k) ), * otherwise return Double.NaN. */ public static double eulerNumber(double n, double k) { if (Double.isNaN(n) || Double.isNaN(k)) return Double.NaN; return eulerNumber( (int)Math.round(n), (int)Math.round(k) ); } /** * Factorial * * @param n the n function parameter * * @return Factorial if n >=0, otherwise returns Double.NaN. */ public static double factorial(int n) { double f = Double.NaN; if (n >= 0) if (n < 2) f = 1; else { f = 1; for (int i = 1; i <= n; i++) { f = f*i; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } } return f; } /** * Factorial * * @param n the n function parameter * * @return if n <> Double.NaN return factorial( (int)Math.round(n) ), * otherwise returns Double.NaN. */ public static double factorial(double n) { if (Double.isNaN(n)) return Double.NaN; return factorial( (int)Math.round(n) ); } /** * Falling factorial polynomial * @param x Argument * @param n Polynomial degree * @return Falling factorial polynomial of degree n at point x */ public static double factorialFalling(double x, double n){ if (Double.isNaN(x)) return Double.NaN; if (Double.isNaN(n)) return Double.NaN; if (n < 0) return Double.NaN; if (BinaryRelations.isEqualOrAlmost(n, 0)) return 1.0; double k, y; y = 1; for (k = 0; k <= n - 1; k = k + 1) { if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; y = y * (x - k); } return y; } /** * Rising factorial polynomial * @param x Argument * @param n Polynomial degree * @return Rising factorial polynomial of degree n at point x */ public static double factorialRising(double x, double n){ if (Double.isNaN(x)) return Double.NaN; if (Double.isNaN(n)) return Double.NaN; if (n < 0) return Double.NaN; if (BinaryRelations.isEqualOrAlmost(n, 0)) return 1.0; double k, y; y = 1; for (k = 0; k <= n - 1; k = k + 1) { if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; y = y * (x + k); } return y; } /** * Generalized binomial coefficient * * @param n the n function parameter * @param k k the k function parameter * * @return Generalized binomial coefficient, if * n = Double.NaN or k < 0 returns Double.NaN. */ public static double binomCoeff(double n, long k) { if (Double.isNaN(n)) return Double.NaN; double result = Double.NaN; if ( k >= 0 ){ double numerator = 1; if (k > 0 ) for (long i = 0; i <= k-1; i++) { numerator*=(n-i); if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } double denominator = 1; if ( k > 1 ) for (long i = 1; i <= k; i++) { denominator *= i; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } result = numerator / denominator; } return result; } /** * Generalized binomial coefficient * * @param n the n function parameter * @param k the k function parameter * * @return if n, k <> Double.NaN returns binomCoeff(n, (int)Math.round(k) ), * otherwise returns Double.NaN. */ public static double binomCoeff(double n, double k) { if (Double.isNaN(n) || Double.isNaN(k)) return Double.NaN; return binomCoeff(n, Math.round(k)); } /** * Generalized coefficient returning number of k permutations * that can be drawn for n elements set. * * @param n the n function parameter * @param k the k function parameter * * @return For k greater than 0 return number of permutations, otherwise * returns Double.NaN */ public static double numberOfPermutations(double n, long k) { if (Double.isNaN(n)) return Double.NaN; double result = Double.NaN; if ( k >= 0 ){ double numerator = 1; if (k > 0 ) for (long i = 0; i <= k-1; i++) { numerator*=(n-i); if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } result = numerator; } return result; } /** * Generalized coefficient returning number of k permutations * that can be drawn for n elements set. * * @param n the n function parameter * @param k the k function parameter * * @return For k greater than 0 return number of permutations, otherwise * returns Double.NaN */ public static double numberOfPermutations(double n, double k) { if (Double.isNaN(n) || Double.isNaN(k)) return Double.NaN; return numberOfPermutations(n, Math.round(k)); } /** * Bernoulli numbers * * @param m the m function parameter * @param n the n function parameter * * @return if n, m >= 0 returns Bernoulli number, * otherwise returns Double.NaN. */ public static double bernoulliNumber(int m, int n) { double result = Double.NaN; if ( (m >= 0) && (n >= 0) ) { result = 0; for (int k = 0; k <= m; k++) for (int v = 0; v <= k; v++) { result += Math.pow(-1, v) * binomCoeff(k, v) * ( Math.pow(n + v, m) / (k + 1) ); if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } } return result; } /** * Bernoulli numbers * * @param m the m function parameter * @param n the n function parameter * * @return if n, m <> Double.NaN returns bernoulliNumber( (int)Math.round(m), (int)Math.round(n) ), * otherwise returns Double.NaN. */ public static double bernoulliNumber(double m, double n) { if (Double.isNaN(m) || Double.isNaN(n)) return Double.NaN; return bernoulliNumber( (int)Math.round(m), (int)Math.round(n) ); } /** * Stirling numbers of the first kind * * @param n the n function parameter * @param k the k function parameter * * @return Stirling numbers of the first kind * Returns also Double.NaN when MAX RECURSION CALLS * is exceeded. * * @see mXparser#getMaxAllowedRecursionDepth() * @see mXparser#setMaxAllowedRecursionDepth(int) */ public static double Stirling1Number(int n, int k) { refreshMaxAllowedRecursionDepth(); return Stirling1Number(n, k, 1); } private static double Stirling1Number(int n, int k, int recursionCall) { if (recursionCall > MAX_RECURSION_CALLS) return Double.NaN; if (k > n) return 0; if (n == 0) if (k == 0) return 1; else return 0; if (k == 0) return 0; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; double s1 = Stirling1Number(n - 1, k, recursionCall + 1); if (Double.isNaN(s1)) return Double.NaN; double s2 = Stirling1Number(n - 1, k - 1, recursionCall + 1); if (Double.isNaN(s2)) return Double.NaN; return (n - 1) * s1 + s2; } /** * Stirling numbers of the first kind * * @param n the n function parameter * @param k the k function parameter * * @return if n, k <> Doube.NaN returns Stirling1Number( (int)Math.round(n), (int)Math.round(k) ), * otherwise returns Double.NaN. */ public static double Stirling1Number(double n, double k) { if (Double.isNaN(n) || Double.isNaN(k)) return Double.NaN; return Stirling1Number( (int)Math.round(n), (int)Math.round(k) ); } /** * Stirling numbers of the second kind * * @param n the n function parameter * @param k the k function parameter * * @return Stirling numbers of the second kind * Returns also Double.NaN when MAX RECURSION CALLS * is exceeded. * * @see mXparser#getMaxAllowedRecursionDepth() * @see mXparser#setMaxAllowedRecursionDepth(int) */ public static double Stirling2Number(int n, int k) { refreshMaxAllowedRecursionDepth(); return Stirling2Number(n, k, 1); } private static double Stirling2Number(int n, int k, int recursionCall) { if (recursionCall > MAX_RECURSION_CALLS) return Double.NaN; if (k > n) return 0; if (n == 0) if (k == 0) return 1; else return 0; if (k == 0) return 0; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; double s1 = Stirling2Number(n - 1, k, recursionCall + 1); if (Double.isNaN(s1)) return Double.NaN; double s2 = Stirling2Number(n - 1, k - 1, recursionCall + 1); if (Double.isNaN(s2)) return Double.NaN; return k * s1 + s2; } /** * Stirling numbers of the second kind * * @param n the n function parameter * @param k the k function parameter * * @return if n, k <> Doube.NaN returns Stirling2Number( (int)Math.round(n), (int)Math.round(k) ), * otherwise returns Double.NaN. */ public static double Stirling2Number(double n, double k) { if (Double.isNaN(n) || Double.isNaN(k)) return Double.NaN; return Stirling2Number( (int)Math.round(n), (int)Math.round(k) ); } /** * Worpitzky numbers * * @param n the n function parameter * @param k the k function parameter * * @return if n,k >= 0 and k <= n return Worpitzky number, * otherwise return Double.NaN. */ public static double worpitzkyNumber(int n, int k) { double result = Double.NaN; if (k >= 0 && k <= n) { result = 0; for (int v = 0; v <= k; v++) { result += Math.pow(-1, v+k) * Math.pow(v+1, n) * binomCoeff(k, v); if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } } return result; } /** * Worpitzky numbers * * @param n the n function parameter * @param k the k function parameter * * @return if n,k <> Double.NaN returns worpitzkyNumber( (int)Math.round(n), (int)Math.round(k) ), * otherwise return Double.NaN. */ public static double worpitzkyNumber(double n, double k) { if (Double.isNaN(n) || Double.isNaN(k)) return Double.NaN; return worpitzkyNumber( (int)Math.round(n), (int)Math.round(k) ); } /** * Harmonic numer * * @param n the n function parameter * * @return if n > 0 returns harmonic number, otherwise returns 0 * (empty summation operator) */ public static double harmonicNumber(int n) { if (n <= 0) return 0; if (n == 1) return 1; double h = 1; for (double k = 2.0; k <= n; k++) { h += 1.0 / k; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } return h; } /** * Harmonic number * * @param n the n function parameter * * @return if n <> Double.NaN returns harmonicNumber( (int)Math.round(n) ), * otherwise returns Double.NaN */ public static double harmonicNumber(double n) { if (Double.isNaN(n)) return Double.NaN; return harmonicNumber( (int)Math.round(n) ); } /** * Harmonic number 1/1 + 1/2^x + ... + 1/n^x * * @param x the x function parameter * @param n the n function parameter * * @return if x <> Double.NaN and x >= 0 Harmonic number, * otherwise returns Double.NaN. */ public static double harmonicNumber(double x, int n) { if ( (Double.isNaN(x)) || (x < 0) ) return Double.NaN; if (n <= 0) return 0; if (n == 1) return x; double h = 1; for (double k = 2.0; k <= n; k++) { h += 1 / power(k, x); if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } return h; } /** * Harmonic number 1/1 + 1/2^x + ... + 1/n^x * * @param x the x function parameter * @param n the n function parameter * * @return if x,n <> Double.NaN returns harmonicNumber( x, (int)Math.round(n) ), * otherwise returns Double.NaN. */ public static double harmonicNumber(double x, double n) { if ( (Double.isNaN(x)) || (Double.isNaN(n)) ) return Double.NaN; return harmonicNumber( x, (int)Math.round(n) ); } /** * Catalan numbers * * @param n the n function parameter * * @return Catalan numbers */ public static double catalanNumber(int n) { return binomCoeff(2*n, n) * div(1, n+1); } /** * Catalan numbers * * @param n the n function parameter * * @return if n <> Double.NaN returns catalanNumber( (int)Math.round(n) ), * otherwise returns Double.NaN. */ public static double catalanNumber(double n) { if (Double.isNaN(n)) return Double.NaN; return catalanNumber( (int)Math.round(n) ); } /** * Fibonacci numbers * * @param n the n function parameter * * @return if n >= 0 returns fibonacci numbers, * otherwise returns Double.NaN. * Returns also Double.NaN when MAX RECURSION CALLS * is exceeded. * * @see mXparser#getMaxAllowedRecursionDepth() * @see mXparser#setMaxAllowedRecursionDepth(int) */ public static double fibonacciNumber(int n) { refreshMaxAllowedRecursionDepth(); return fibonacciNumber(n, 1); } private static double fibonacciNumber(int n, int recursionCall) { if (recursionCall > MAX_RECURSION_CALLS) return Double.NaN; if (n < 0) return Double.NaN; if (n == 0) return 0; if (n == 1) return 1; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; double f1 = fibonacciNumber(n - 1, recursionCall + 1); if (Double.isNaN(f1)) return Double.NaN; double f2 = fibonacciNumber(n - 2, recursionCall + 1); if (Double.isNaN(f2)) return Double.NaN; return f1 + f2; } /** * Fibonacci numbers * * @param n the n function parameter * * @return if n <> Double.NaN returns fibonacciNumber( (int)Math.round(n) ), * otherwise returns Double.NaN. */ public static double fibonacciNumber(double n) { if (Double.isNaN(n)) return Double.NaN; return fibonacciNumber( (int)Math.round(n) ); } /** * Lucas numebrs * * @param n the n function parameter * * @return if n >= 0 returns Lucas numbers, * otherwise returns Double.NaN. * Returns also Double.NaN when MAX RECURSION CALLS * is exceeded. * * @see mXparser#getMaxAllowedRecursionDepth() * @see mXparser#setMaxAllowedRecursionDepth(int) */ public static double lucasNumber(int n) { refreshMaxAllowedRecursionDepth(); return lucasNumber(n, 1); } private static double lucasNumber(int n, int recursionCall) { if (recursionCall > MAX_RECURSION_CALLS) return Double.NaN; if (n < 0) return Double.NaN; if (n == 0) return 2; if (n == 1) return 1; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; double l1 = lucasNumber(n - 1, recursionCall + 1); if (Double.isNaN(l1)) return Double.NaN; double l2 = lucasNumber(n - 2, recursionCall + 1); if (Double.isNaN(l2)) return Double.NaN; return l1 + l2; } /** * Lucas numebrs * * @param n the n function parameter * * @return if n <> Double.NaN returns lucasNumber( (int)Math.round(n) ), * otherwise returns Double.NaN. */ public static double lucasNumber(double n) { if (Double.isNaN(n)) return Double.NaN; return lucasNumber( (int)Math.round(n) ); } /** * Kronecker delta * * @param i the i function parameter * @param j the j function parameter * * @return if i,j <> Double.NaN returns Kronecker delta, * otherwise returns Double.NaN. */ public static double kroneckerDelta(double i, double j) { if (Double.isNaN(i) || Double.isNaN(j)) return Double.NaN; if (i == j) return 1; else return 0; } /** * Kronecker delta * * @param i the i function parameter * @param j the j function parameter * * @return Kronecker delta */ public static double kroneckerDelta(int i, int j) { if (i == j) return 1; else return 0; } /** * Continued fraction * * @param sequence the numbers * * @return if each number form the sequence <> Double.NaN and * there is no division by 0 while computing returns continued fraction * value, otherwise returns Double.NaN. */ public static double continuedFraction(double... sequence) { if (sequence == null) return Double.NaN; if (sequence.length == 0) return Double.NaN; double cf = 0; double a; if (sequence.length == 1) return sequence[0]; int lastIndex = sequence.length-1; for(int i = lastIndex; i >= 0; i--) { a = sequence[i]; if (Double.isNaN(a)) return Double.NaN; if (i == lastIndex) { cf = a; } else { if (cf == 0) return Double.NaN; cf = a + 1.0 / cf; } if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } return cf; } /** * Private function calculating continued polynomial * recursively. * * @param n the polynomial order * @param x the x values * * @return continued polynomial value */ private static double continuedPolynomial(int n, double[] x) { if (x == null) return Double.NaN; if (x.length == 0) return Double.NaN; if (n == 0) return 1; if (n == 1) return x[0]; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; return x[n-1] * continuedPolynomial(n-1, x) + continuedPolynomial(n-2, x); } /** * Continued polynomial * * @param x the x values * * @return if each number for x is different the Double.NaN * returns continued polynomial, otherwise returns * Double.NaN. */ public static double continuedPolynomial(double... x) { if (x == null) return Double.NaN; if (x.length == 0) return Double.NaN; for (double d : x) { if (Double.isNaN(d)) return Double.NaN; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } return continuedPolynomial(x.length, x); } /** * Euler polynomial * * @param m the m parameter * @param x the x parameter * * @return if x <> Double.NaN and m >= 0 returns polynomial value, * otherwise returns Double.NaN. */ public static double eulerPolynomial(int m, double x) { if (Double.isNaN(x)) return Double.NaN; double sumTotal = Double.NaN; if (m >= 0) { sumTotal = 0; for (int n = 0; n <= m; n++) { double sumPartial = 0; for (int k = 0; k <= n; k++) { sumPartial += Math.pow(-1, k) * binomCoeff(n, k) * Math.pow(x+k, m); if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } sumPartial /= Math.pow(2, n); sumTotal += sumPartial; } } return sumTotal; } /** * Euler polynomial * * @param m the m parameter * @param x the x parameter * * @return if x,m <> Double.NaN returns eulerPolynomial( (int)Math.round(m), (int)Math.round(x) ), * otherwise returns Double.NaN. */ public static double eulerPolynomial(double m, double x) { if (Double.isNaN(m) || Double.isNaN(x)) return Double.NaN; return eulerPolynomial( (int)Math.round(m), x); } /** * Characteristic function x in (a,b) * * @param x the x value * @param a the left (lower) limit * @param b the right (upper) limit * * @return if x, a, b <> Double.NaN returns * characteristic function value on the (a,b) range. */ public static double chi(double x, double a, double b) { if (Double.isNaN(x) || Double.isNaN(a) || Double.isNaN(b)) return Double.NaN; double result = Double.NaN; if ( (!Double.isNaN(x)) && (!Double.isNaN(a)) && (!Double.isNaN(b)) ) if ( (x > a) && (x < b) ) result = 1; else result = 0; return result; } /** * Characteristic function x in [a,b] * * @param x the x value * @param a the left (lower) limit * @param b the right (upper) limit * * @return if x, a, b <> Double.NaN returns * characteristic function value on the [a,b] range. */ public static double chi_LR(double x, double a, double b) { if (Double.isNaN(x) || Double.isNaN(a) || Double.isNaN(b)) return Double.NaN; double result = Double.NaN; if ( (!Double.isNaN(x)) && (!Double.isNaN(a)) && (!Double.isNaN(b)) ) if ( (x >= a) && (x <= b) ) result = 1; else result = 0; return result; } /** * Characteristic function x in [a,b) * * @param x the x value * @param a the left (lower) limit * @param b the right (upper) limit * * @return if x, a, b <> Double.NaN returns * characteristic function value on the [a,b) range. */ public static double chi_L(double x, double a, double b) { if (Double.isNaN(x) || Double.isNaN(a) || Double.isNaN(b)) return Double.NaN; double result = Double.NaN; if ( (!Double.isNaN(x)) && (!Double.isNaN(a)) && (!Double.isNaN(b)) ) if ( (x >= a) && (x < b) ) result = 1; else result = 0; return result; } /** * Characteristic function x in (a,b] * * @param x the x value * @param a the left (lower) limit * @param b the right (upper) limit * * @return if x, a, b <> Double.NaN returns * characteristic function value on the (a,b] range. */ public static double chi_R(double x, double a, double b) { if (Double.isNaN(x) || Double.isNaN(a) || Double.isNaN(b)) return Double.NaN; double result = Double.NaN; if ( (!Double.isNaN(x)) && (!Double.isNaN(a)) && (!Double.isNaN(b)) ) if ( (x > a) && (x <= b) ) result = 1; else result = 0; return result; } /** * Verifies whether provided number is almost integer * * @see BinaryRelations#DEFAULT_COMPARISON_EPSILON * * @param a The number to be verified * @return True if the number is almost integer according to the default epsilon, * otherwise returns false. */ public static boolean isAlmostInt(double a) { double aint = Math.round(a); return abs(a - aint) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON; } /** * Applies the integer exponent to the base a * * @param a The base * @param n The integer exponent * @return Return a to the power of n, if canonical rounding is enable, the it operates on big numbers */ private static double powInt(double a, int n) { if (Double.isNaN(a)) return Double.NaN; if (Double.isInfinite(a)) return Math.pow(a, n); if (a == 0) return Math.pow(a, n); if (n == 0) return 1; if (n == 1) return a; if (mXparser.checkIfCanonicalRounding()) { BigDecimal da = BigDecimal.valueOf(a); try { if (n >= 0) return da.pow(n).doubleValue(); else return BigDecimal.ONE.divide(da, MathContext.DECIMAL128).pow(-n).doubleValue(); } catch (Throwable e) { return Math.pow(a, n); } } else { return Math.pow(a, n); } } /** * Power function a^b * * @param a the a function parameter * @param b the b function parameter * * @return if a,b <> Double.NaN returns Math.pow(a, b), * otherwise returns Double.NaN. */ public static double power(double a, double b) { if (Double.isNaN(a) || Double.isNaN(b)) return Double.NaN; if (Double.isInfinite(a)) return Math.pow(a, b); if (Double.isInfinite(b)) return Math.pow(a, b); double babs = Math.abs(b); double bint = Math.round(babs); if ( MathFunctions.abs(babs - bint) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON && babs < Integer.MAX_VALUE && -babs > Integer.MIN_VALUE) { if (b >= 0) return powInt(a, (int)bint); else return powInt(a, -(int)bint); } else if (a >= 0) return Math.pow(a, b); else if (abs(b) >= 1) return Math.pow(a, b); else if (b == 0) return Math.pow(a, b); else { double ndob = 1.0 / abs(b); double nint = Math.round(ndob); if ( MathFunctions.abs(ndob-nint) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON ) { long n = (long)nint; if (n % 2 == 1) if (b > 0) return -Math.pow( abs(a), 1.0 / ndob); else return -Math.pow( abs(a), -1.0 / ndob); else return Double.NaN; } else return Double.NaN; } } /** * Nth order root of a number * * @param n Root order * @param x Number * @return Returns root of a number. If calculation is not possible Double.NaN is returned. */ public static double root(double n, double x) { if (Double.isNaN(n) || Double.isNaN(x)) return Double.NaN; if (Double.isInfinite(n) || Double.isInfinite(x)) return Double.NaN; if (n < -BinaryRelations.DEFAULT_COMPARISON_EPSILON) return Double.NaN; if (abs(n) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON) { if (abs(x) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON) return 0; else if (abs(x-1) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON) return 1; else return Double.NaN; } long nint = (long)floor(n); if (nint == 1) return x; if (nint == 2) return sqrt(x); if (nint % 2 == 1) { if ( x >= 0) return Math.pow(x, 1.0 / nint); else return -Math.pow( abs(x), 1.0 / nint); } else { if ( x >= 0) return Math.pow(x, 1.0 / nint); else return Double.NaN; } } /** * Tetration, exponential power, power series * * @param a base * @param n exponent * @return Tetration result. */ public static double tetration(double a, double n) { if (Double.isNaN(a)) return Double.NaN; if (Double.isNaN(n)) return Double.NaN; if (n == Double.POSITIVE_INFINITY) { if (BinaryRelations.isEqualOrAlmost(a, 1)) return 1.0; if (abs(a - MathConstants.EXP_MINUS_E) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON) return MathConstants.EXP_MINUS_1; if (abs(a - MathConstants.EXP_1_OVER_E) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON) return MathConstants.E; if ((a > MathConstants.EXP_MINUS_E) && (a < MathConstants.EXP_1_OVER_E)) return SpecialFunctions.lambertW( -MathFunctions.ln(a), 0) / ( -MathFunctions.ln(a) ); if (a > MathConstants.EXP_1_OVER_E) return Double.POSITIVE_INFINITY; if (a < MathConstants.EXP_MINUS_E) return Double.NaN; } if (n < -BinaryRelations.DEFAULT_COMPARISON_EPSILON) return Double.NaN; if (abs(n) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON) { if (abs(a) > BinaryRelations.DEFAULT_COMPARISON_EPSILON) return 1; else return Double.NaN; } n = floor(n); if (n == 0) { if (abs(a) > BinaryRelations.DEFAULT_COMPARISON_EPSILON) return 1; else return Double.NaN; } if (abs(a) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON) return 0; if (n == 1) return a; double r = a; for (double i = 2; i <= n; i++) { r = Math.pow(a, r); if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } return r; } /** * Modulo operator a % b * * @param a the a function parameter * @param b the b function parameter * * @return if a,b <> Double.NaN returns a % b. */ public static double mod(double a, double b) { if (Double.isNaN(a) || Double.isNaN(b)) return Double.NaN; return a % b; } /** * Division a/b * * @param a the a function parameter * @param b the b function parameter * * @return if a,b <> Double.NaN and b <> 0 returns a/b, * otherwise return Double.NaN. */ /* public static final double div(double a, double b) { if (Double.isNaN(a) || Double.isNaN(b)) return Double.NaN; double result = Double.NaN; if (b != 0) result = a / b; return result; } */ /** * Sine trigonometric function * * @param a the a function parameter * * @return if a <> Double.NaN return Math.sin(a), * otherwise return Double.NaN. */ public static double sin(double a) { if (Double.isNaN(a)) return Double.NaN; if (mXparser.checkIfDegreesMode()) a = a * Units.DEGREE_ARC; SpecialValueTrigonometric sv = SpecialValueTrigonometric.getSpecialValueTrigonometric(a); if (sv != null) return sv.sin; return Math.sin(a); } /** * Cosine trigonometric function * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.cos(a), * otherwise returns Double.NaN. */ public static double cos(double a) { if (Double.isNaN(a)) return Double.NaN; if (mXparser.checkIfDegreesMode()) a = a * Units.DEGREE_ARC; SpecialValueTrigonometric sv = SpecialValueTrigonometric.getSpecialValueTrigonometric(a); if (sv != null) return sv.cos; return Math.cos(a); } /** * Tangent trigonometric function * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.tan(a), * otherwise returns Double.NaN. */ public static double tan(double a) { if (Double.isNaN(a)) return Double.NaN; if (mXparser.checkIfDegreesMode()) a = a * Units.DEGREE_ARC; SpecialValueTrigonometric sv = SpecialValueTrigonometric.getSpecialValueTrigonometric(a); if (sv != null) return sv.tan; return Math.tan(a); } /** * Cotangent trigonometric function * * @param a the a function parameter * * @return if a <> Double.NaN and tan(a) <> 0 returns 1 / Math.tan(a), * otherwise returns Double.NaN. */ public static double ctan(double a) { if (Double.isNaN(a)) return Double.NaN; if (mXparser.checkIfDegreesMode()) a = a * Units.DEGREE_ARC; SpecialValueTrigonometric sv = SpecialValueTrigonometric.getSpecialValueTrigonometric(a); if (sv != null) return sv.ctan; double result = Double.NaN; double tg = Math.tan(a); if (tg != 0) result = 1.0 / tg; return result; } /** * Secant trigonometric function * * @param a the a function parameter * * @return if a <> Double.NaN and cos(a) <> 0 returns 1 / Math.cos(a), * otherwise returns Double.NaN. */ public static double sec(double a) { if (Double.isNaN(a)) return Double.NaN; if (mXparser.checkIfDegreesMode()) a = a * Units.DEGREE_ARC; SpecialValueTrigonometric sv = SpecialValueTrigonometric.getSpecialValueTrigonometric(a); if (sv != null) return sv.sec; double result = Double.NaN; double cos = Math.cos(a); if (cos != 0) result = 1.0 / cos; return result; } /** * Cosecant trigonometric function * * @param a the a function parameter * * @return if a <> Double.NaN and sin(a) <> 0 returns 1 / Math.sin(a), * otherwise returns Double.NaN. */ public static double cosec(double a) { if (Double.isNaN(a)) return Double.NaN; if (mXparser.checkIfDegreesMode()) a = a * Units.DEGREE_ARC; SpecialValueTrigonometric sv = SpecialValueTrigonometric.getSpecialValueTrigonometric(a); if (sv != null) return sv.csc; double result = Double.NaN; double sin = Math.sin(a); if (sin != 0) result = 1.0 / sin; return result; } /** * If double is almost integer returns the closes integer, otherwise original value * @param val Parameter * @return f double is almost integer returns the closest integer, otherwise original value */ private static double intIfAlmostIntOtherwiseOrig(double val) { double valint = Math.round(val); if ( Math.abs(val-valint) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON ) return valint; return val; } /** * Arcus sine - inverse trigonometric sine function * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.asin(a), * otherwise returns Double.NaN. */ public static double asin(double a) { if (Double.isNaN(a)) return Double.NaN; SpecialValue sv = SpecialValueTrigonometric.getSpecialValueAsin(a); double r; if (sv != null) r = sv.fv; else r = Math.asin(a); if (mXparser.checkIfDegreesMode()) { if (sv != null) return sv.fvdeg; return intIfAlmostIntOtherwiseOrig(div(r, Units.DEGREE_ARC)); } else return r; } /** * Arcus cosine - inverse trigonometric cosine function * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.acos(a), * otherwise returns Double.NaN. */ public static double acos(double a) { if (Double.isNaN(a)) return Double.NaN; SpecialValue sv = SpecialValueTrigonometric.getSpecialValueAcos(a); double r; if (sv != null) r = sv.fv; else r = Math.acos(a); if (mXparser.checkIfDegreesMode()) { if (sv != null) return sv.fvdeg; return intIfAlmostIntOtherwiseOrig(div(r, Units.DEGREE_ARC)); } else return r; } /** * Arcus tangent - inverse trigonometric tangent function * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.atan(a), * otherwise returns Double.NaN. */ public static double atan(double a) { if (Double.isNaN(a)) return Double.NaN; SpecialValue sv = SpecialValueTrigonometric.getSpecialValueAtan(a); double r; if (sv != null) r = sv.fv; else r = Math.atan(a); if (mXparser.checkIfDegreesMode()) { if (sv != null) return sv.fvdeg; return intIfAlmostIntOtherwiseOrig(div(r, Units.DEGREE_ARC)); } else return r; } /** * Arcus cotangent - inverse trigonometric cotangent function * * @param a the a function parameter * * @return if a <> Double.NaN and a <> 0 returns Math.atan(1/a), * otherwise returns Double.NaN. */ public static double actan(double a) { if (Double.isNaN(a)) return Double.NaN; SpecialValue sv = SpecialValueTrigonometric.getSpecialValueActan(a); double r; if (sv != null) r = sv.fv; else { if (a > 0) r = Math.atan(1/a); else if (a < 0) r = Math.atan(1/a) + MathConstants.PI; else r = Double.NaN; } if (mXparser.checkIfDegreesMode()) { if (sv != null) return sv.fvdeg; return intIfAlmostIntOtherwiseOrig(div(r, Units.DEGREE_ARC)); } else return r; } /** * Arcus secant - inverse trigonometric secant function * * @param a the a function parameter * @return Inverse trigonometric secant function */ public static double asec(double a) { if (Double.isNaN(a)) return Double.NaN; SpecialValue sv = SpecialValueTrigonometric.getSpecialValueAsec(a); double r; if (sv != null) r = sv.fv; else r = Math.acos(1/a); if (mXparser.checkIfDegreesMode()) { if (sv != null) return sv.fvdeg; return intIfAlmostIntOtherwiseOrig(div(r, Units.DEGREE_ARC)); } else return r; } /** * Arcus cosecant - inverse trigonometric cosecant function * * @param a the a function parameter * @return Inverse trigonometric cosecant function */ public static double acosec(double a) { if (Double.isNaN(a)) return Double.NaN; SpecialValue sv = SpecialValueTrigonometric.getSpecialValueAcsc(a); double r; if (sv != null) r = sv.fv; else r = Math.asin(1/a); if (mXparser.checkIfDegreesMode()) { if (sv != null) return sv.fvdeg; return intIfAlmostIntOtherwiseOrig(div(r, Units.DEGREE_ARC)); } else return r; } /** * Natural logarithm * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.log(1/a), * otherwise returns Double.NaN. */ public static double ln(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.log(a); } /** * Binary logarithm * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.log(a)/Math.log(2.0), * otherwise returns Double.NaN. */ public static double log2(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.log(a)/Math.log(2.0); } /** * Common logarithm * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.log10(a), * otherwise returns Double.NaN. */ public static double log10(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.log10(a); } /** * Degrees to radius translation. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.toRadians(a), * otherwise returns Double.NaN. */ public static double rad(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.toRadians(a); } /** * Exponential function. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.exp(a), * otherwise returns Double.NaN. */ public static double exp(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.exp(a); } /** * Square root. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.sqrt(a), * otherwise returns Double.NaN. */ public static double sqrt(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.sqrt(a); } /** * Hyperbolic sine function. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.sinh(a), * otherwise returns Double.NaN. */ public static double sinh(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.sinh(a); } /** * Hyperbolic cosine function. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.cosh(a), * otherwise returns Double.NaN. */ public static double cosh(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.cosh(a); } /** * Hyperbolic tangent function. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.tanh(a), * otherwise returns Double.NaN. */ public static double tanh(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.tanh(a); } /** * Hyperbolic cotangent function. * * @param a the a function parameter * * @return if a <> Double.NaN and tanh(a) <> 0 returns 1 / Math.tanh(a), * otherwise returns Double.NaN. */ public static double coth(double a) { if (Double.isNaN(a)) return Double.NaN; double result = Double.NaN; double tanh = Math.tanh(a); if (tanh != 0) result = 1.0 / tanh; return result; } /** * Hyperbolic secant function. * * @param a the a function parameter * * @return if a <> Double.NaN and cosh(a) <> 0 returns 1 / Math.cosh(a), * otherwise returns Double.NaN. */ public static double sech(double a) { if (Double.isNaN(a)) return Double.NaN; double result = Double.NaN; double cosh = Math.cosh(a); if (cosh != 0) result = 1.0 / cosh; return result; } /** * Hyperbolic cosecant function. * * @param a the a function parameter * * @return if a <> Double.NaN and sinh(a) <> 0 returns 1 / Math.sinh(a), * otherwise returns Double.NaN. */ public static double csch(double a) { if (Double.isNaN(a)) return Double.NaN; double result = Double.NaN; double sinh = Math.sinh(a); if (sinh != 0) result = 1.0 / sinh; return result; } /** * Radius to degrees translation. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.toDegrees(a), * otherwise returns Double.NaN. */ public static double deg(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.toDegrees(a); } /** * Absolute value. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.abs(a), * otherwise returns Double.NaN. */ public static double abs(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.abs(a); } /** * Signum function. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.signum(a), * otherwise returns Double.NaN. */ public static double sgn(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.signum(a); } /** * Floor function. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.floor(a), * otherwise returns Double.NaN. */ public static double floor(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.floor(a); } /** * Ceiling function. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.ceil(a), * otherwise returns Double.NaN. */ public static double ceil(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.ceil(a); } /** * Arcus hyperbolic sine - inverse hyperbolic sine function. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.log(a + Math.sqrt(a*a+1)), * otherwise returns Double.NaN. */ public static double arsinh(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.log(a + Math.sqrt(a*a+1)); } /** * Arcus hyperbolic cosine - inverse hyperbolic cosine function. * * @param a the a function parameter * * @return if a <> Double.NaN returns Math.log(a + Math.sqrt(a*a-1)), * otherwise returns Double.NaN. */ public static double arcosh(double a) { if (Double.isNaN(a)) return Double.NaN; return Math.log(a + Math.sqrt(a*a-1)); } /** * Arcus hyperbolic tangent - inverse hyperbolic tangent function. * * @param a the a function parameter * * @return if a <> Double.NaN and 1-a <> 0 returns 0.5*Math.log( (1+a)/(1-a) ), * otherwise returns Double.NaN. */ public static double artanh(double a) { if (Double.isNaN(a)) return Double.NaN; double result = Double.NaN; if (1-a != 0) result = 0.5*Math.log( (1+a)/(1-a) ); return result; } /** * Arcus hyperbolic tangent - inverse hyperbolic tangent function. * * @param a the a function parameter * * @return if a <> Double.NaN and a-1 <> 0 returns 0.5*Math.log( (a+1)/(a-1) );, * otherwise returns Double.NaN. */ public static double arcoth(double a) { if (Double.isNaN(a)) return Double.NaN; double result = Double.NaN; if (a-1 != 0) result = 0.5*Math.log( (a+1)/(a-1) ); return result; } /** * Arcus hyperbolic secant - inverse hyperbolic secant function. * * @param a the a function parameter * * @return if a <> Double.NaN and a <> 0 returns Math.log( (1+Math.sqrt(1-a*a))/a);, * otherwise returns Double.NaN. */ public static double arsech(double a) { if (Double.isNaN(a)) return Double.NaN; double result = Double.NaN; if (a != 0) result = Math.log( (1+Math.sqrt(1-a*a))/a); return result; } /** * Arcus hyperbolic cosecant - inverse hyperbolic cosecant function. * * @param a the a function parameter * * @return if a <> Double.NaN and a <> 0 returns Math.log( (1+Math.sqrt(1-a*a))/a);, * otherwise returns Double.NaN. */ public static double arcsch(double a) { if (Double.isNaN(a)) return Double.NaN; double result = Double.NaN; if (a != 0) result = Math.log( 1/a + Math.sqrt(1+a*a)/Math.abs(a) ); return result; } /** * Normalized sinc function. * * @param a the a function parameter * * @return if a <> Double.NaN and a <> 0 returns Math.sin(PI*a) / (PI*a);, * otherwise returns Double.NaN. */ public static double sa(double a) { if (Double.isNaN(a)) return Double.NaN; double x = MathConstants.PI * a; double result = Double.NaN; if (x != 0) result = Math.sin(x) / (x); else result = 1.0; return result; } /** * Sinc function. * * @param a the a function parameter * * @return if a <> Double.NaN and a <> 0 returns Math.sin(a) / (a), * otherwise returns Double.NaN. */ public static double sinc(double a) { if (Double.isNaN(a)) return Double.NaN; double result = Double.NaN; if (a != 0) if (mXparser.checkIfDegreesMode()) result = Math.sin(a * Units.DEGREE_ARC) / (a); else result = Math.sin(a) / (a); else result = 1.0; return result; } /** * General logarithm. * * @param a the a function parameter (base) * @param b the b function parameter (number) * * @return if a,b <> Double.NaN and log(b) <> 0 returns Math.log(a) / Math.log(b), * otherwise returns Double.NaN. */ public static double log(double a, double b) { if (Double.isNaN(a) || Double.isNaN(b)) return Double.NaN; double result = Double.NaN; double logb = Math.log(b); if (logb != 0) result = Math.log(a) / logb; return result; } /** * Double rounding * * @param value double value to be rounded * @param places decimal places * @return Rounded value */ public static double round(double value, int places) { if (Double.isNaN(value)) return Double.NaN; if (Double.isInfinite(value)) return value; if (places < 0) return Double.NaN; try { BigDecimal bd = new BigDecimal(Double.toString(value)); bd = bd.setScale(places, RoundingMode.HALF_UP); return bd.doubleValue(); } catch (Throwable e) { return roundHalfUp(value, places); } } /** * Double half up rounding * * @param value double value to be rounded * @param places decimal places * @return Rounded value */ public static double roundHalfUp(double value, int places) { if (Double.isNaN(value)) return Double.NaN; if (places < 0) return Double.NaN; if (value == Double.NEGATIVE_INFINITY) return Double.NEGATIVE_INFINITY; if (value == Double.POSITIVE_INFINITY) return Double.POSITIVE_INFINITY; if (value == 0) return 0; double sign = 1; double origValue = value; if (value < 0) { sign = -1; value = -value; } int ulpPosition = MathFunctions.ulpDecimalDigitsBefore(value); if (ulpPosition <= 0) return sign * Math.floor(value); if (places > ulpPosition) return origValue; double multiplier = 1; for (int place = 0; place < places; place++) { multiplier = Math.floor(multiplier * 10); if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } double valueMultiplied = value * multiplier; double valueFloor = Math.floor(valueMultiplied); if (Math.abs(valueMultiplied - valueFloor) >= 0.5) valueFloor = Math.floor(valueFloor + 1); return Math.floor(sign * valueFloor) / multiplier; } /** * Double down rounding * * @param value double value to be rounded * @param places decimal places * @return Rounded value */ public static double roundDown(double value, int places) { if (Double.isNaN(value)) return Double.NaN; if (places < 0) return Double.NaN; if (value == Double.NEGATIVE_INFINITY) return Double.NEGATIVE_INFINITY; if (value == Double.POSITIVE_INFINITY) return Double.POSITIVE_INFINITY; if (value == 0) return 0; double sign = 1; double origValue = value; if (value < 0) { sign = -1; value = -value; } int ulpPosition = MathFunctions.ulpDecimalDigitsBefore(value); if (ulpPosition <= 0) return sign * Math.floor(value); if (places > ulpPosition) return origValue; double multiplier = 1; for (int place = 0; place < places; place++) { multiplier = Math.floor(multiplier * 10); if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } double valueMultiplied = value * multiplier; double valueFloor = Math.floor(valueMultiplied); return Math.floor(sign * valueFloor) / multiplier; } /** * Unit in the last place rounding, see * 0.1 + 0.1 + 0.1 vs roundUlp(0.1 + 0.1 + 0.1) * * @param number Double number that is to be rounded * * @return Double number with rounded ulp * * @see MathFunctions#decimalDigitsBefore(double) * @see MathFunctions#ulp(double) */ public static double roundUlp(double number) { if ( (Double.isNaN(number) ) || (Double.isInfinite(number)) || (number == 0) ) return number; else { int precision = MathFunctions.ulpDecimalDigitsBefore(number); if (precision >= 1) return MathFunctions.round(number, precision-5); else if (precision == 0) return MathFunctions.round(number, 0); else return number; } } /** * Returns integer part of a double value. * @param x Number * @return For non-negative x returns Math.floor(x), * otherwise returns -Math.floor(-x) */ public static double integerPart(double x) { if (x > 0) return Math.floor(x); else if (x < 0) return -Math.floor(-x); else return 0; } /** * For very small number returns the position of * first significant digit, ie 0.1 = 1, 0.01 = 2 * * @param value Double value, small one. * @return Number of digits, number of places. */ public static int decimalDigitsBefore(double value) { if (value == 0) return -1; if (value <= 1e-322) return 322; else if (value <= 1e-321) return 321; else if (value <= 1e-320) return 320; else if (value <= 1e-319) return 319; else if (value <= 1e-318) return 318; else if (value <= 1e-317) return 317; else if (value <= 1e-316) return 316; else if (value <= 1e-315) return 315; else if (value <= 1e-314) return 314; else if (value <= 1e-313) return 313; else if (value <= 1e-312) return 312; else if (value <= 1e-311) return 311; else if (value <= 1e-310) return 310; else if (value <= 1e-309) return 309; else if (value <= 1e-308) return 308; else if (value <= 1e-307) return 307; else if (value <= 1e-306) return 306; else if (value <= 1e-305) return 305; else if (value <= 1e-304) return 304; else if (value <= 1e-303) return 303; else if (value <= 1e-302) return 302; else if (value <= 1e-301) return 301; else if (value <= 1e-300) return 300; else if (value <= 1e-299) return 299; else if (value <= 1e-298) return 298; else if (value <= 1e-297) return 297; else if (value <= 1e-296) return 296; else if (value <= 1e-295) return 295; else if (value <= 1e-294) return 294; else if (value <= 1e-293) return 293; else if (value <= 1e-292) return 292; else if (value <= 1e-291) return 291; else if (value <= 1e-290) return 290; else if (value <= 1e-289) return 289; else if (value <= 1e-288) return 288; else if (value <= 1e-287) return 287; else if (value <= 1e-286) return 286; else if (value <= 1e-285) return 285; else if (value <= 1e-284) return 284; else if (value <= 1e-283) return 283; else if (value <= 1e-282) return 282; else if (value <= 1e-281) return 281; else if (value <= 1e-280) return 280; else if (value <= 1e-279) return 279; else if (value <= 1e-278) return 278; else if (value <= 1e-277) return 277; else if (value <= 1e-276) return 276; else if (value <= 1e-275) return 275; else if (value <= 1e-274) return 274; else if (value <= 1e-273) return 273; else if (value <= 1e-272) return 272; else if (value <= 1e-271) return 271; else if (value <= 1e-270) return 270; else if (value <= 1e-269) return 269; else if (value <= 1e-268) return 268; else if (value <= 1e-267) return 267; else if (value <= 1e-266) return 266; else if (value <= 1e-265) return 265; else if (value <= 1e-264) return 264; else if (value <= 1e-263) return 263; else if (value <= 1e-262) return 262; else if (value <= 1e-261) return 261; else if (value <= 1e-260) return 260; else if (value <= 1e-259) return 259; else if (value <= 1e-258) return 258; else if (value <= 1e-257) return 257; else if (value <= 1e-256) return 256; else if (value <= 1e-255) return 255; else if (value <= 1e-254) return 254; else if (value <= 1e-253) return 253; else if (value <= 1e-252) return 252; else if (value <= 1e-251) return 251; else if (value <= 1e-250) return 250; else if (value <= 1e-249) return 249; else if (value <= 1e-248) return 248; else if (value <= 1e-247) return 247; else if (value <= 1e-246) return 246; else if (value <= 1e-245) return 245; else if (value <= 1e-244) return 244; else if (value <= 1e-243) return 243; else if (value <= 1e-242) return 242; else if (value <= 1e-241) return 241; else if (value <= 1e-240) return 240; else if (value <= 1e-239) return 239; else if (value <= 1e-238) return 238; else if (value <= 1e-237) return 237; else if (value <= 1e-236) return 236; else if (value <= 1e-235) return 235; else if (value <= 1e-234) return 234; else if (value <= 1e-233) return 233; else if (value <= 1e-232) return 232; else if (value <= 1e-231) return 231; else if (value <= 1e-230) return 230; else if (value <= 1e-229) return 229; else if (value <= 1e-228) return 228; else if (value <= 1e-227) return 227; else if (value <= 1e-226) return 226; else if (value <= 1e-225) return 225; else if (value <= 1e-224) return 224; else if (value <= 1e-223) return 223; else if (value <= 1e-222) return 222; else if (value <= 1e-221) return 221; else if (value <= 1e-220) return 220; else if (value <= 1e-219) return 219; else if (value <= 1e-218) return 218; else if (value <= 1e-217) return 217; else if (value <= 1e-216) return 216; else if (value <= 1e-215) return 215; else if (value <= 1e-214) return 214; else if (value <= 1e-213) return 213; else if (value <= 1e-212) return 212; else if (value <= 1e-211) return 211; else if (value <= 1e-210) return 210; else if (value <= 1e-209) return 209; else if (value <= 1e-208) return 208; else if (value <= 1e-207) return 207; else if (value <= 1e-206) return 206; else if (value <= 1e-205) return 205; else if (value <= 1e-204) return 204; else if (value <= 1e-203) return 203; else if (value <= 1e-202) return 202; else if (value <= 1e-201) return 201; else if (value <= 1e-200) return 200; else if (value <= 1e-199) return 199; else if (value <= 1e-198) return 198; else if (value <= 1e-197) return 197; else if (value <= 1e-196) return 196; else if (value <= 1e-195) return 195; else if (value <= 1e-194) return 194; else if (value <= 1e-193) return 193; else if (value <= 1e-192) return 192; else if (value <= 1e-191) return 191; else if (value <= 1e-190) return 190; else if (value <= 1e-189) return 189; else if (value <= 1e-188) return 188; else if (value <= 1e-187) return 187; else if (value <= 1e-186) return 186; else if (value <= 1e-185) return 185; else if (value <= 1e-184) return 184; else if (value <= 1e-183) return 183; else if (value <= 1e-182) return 182; else if (value <= 1e-181) return 181; else if (value <= 1e-180) return 180; else if (value <= 1e-179) return 179; else if (value <= 1e-178) return 178; else if (value <= 1e-177) return 177; else if (value <= 1e-176) return 176; else if (value <= 1e-175) return 175; else if (value <= 1e-174) return 174; else if (value <= 1e-173) return 173; else if (value <= 1e-172) return 172; else if (value <= 1e-171) return 171; else if (value <= 1e-170) return 170; else if (value <= 1e-169) return 169; else if (value <= 1e-168) return 168; else if (value <= 1e-167) return 167; else if (value <= 1e-166) return 166; else if (value <= 1e-165) return 165; else if (value <= 1e-164) return 164; else if (value <= 1e-163) return 163; else if (value <= 1e-162) return 162; else if (value <= 1e-161) return 161; else if (value <= 1e-160) return 160; else if (value <= 1e-159) return 159; else if (value <= 1e-158) return 158; else if (value <= 1e-157) return 157; else if (value <= 1e-156) return 156; else if (value <= 1e-155) return 155; else if (value <= 1e-154) return 154; else if (value <= 1e-153) return 153; else if (value <= 1e-152) return 152; else if (value <= 1e-151) return 151; else if (value <= 1e-150) return 150; else if (value <= 1e-149) return 149; else if (value <= 1e-148) return 148; else if (value <= 1e-147) return 147; else if (value <= 1e-146) return 146; else if (value <= 1e-145) return 145; else if (value <= 1e-144) return 144; else if (value <= 1e-143) return 143; else if (value <= 1e-142) return 142; else if (value <= 1e-141) return 141; else if (value <= 1e-140) return 140; else if (value <= 1e-139) return 139; else if (value <= 1e-138) return 138; else if (value <= 1e-137) return 137; else if (value <= 1e-136) return 136; else if (value <= 1e-135) return 135; else if (value <= 1e-134) return 134; else if (value <= 1e-133) return 133; else if (value <= 1e-132) return 132; else if (value <= 1e-131) return 131; else if (value <= 1e-130) return 130; else if (value <= 1e-129) return 129; else if (value <= 1e-128) return 128; else if (value <= 1e-127) return 127; else if (value <= 1e-126) return 126; else if (value <= 1e-125) return 125; else if (value <= 1e-124) return 124; else if (value <= 1e-123) return 123; else if (value <= 1e-122) return 122; else if (value <= 1e-121) return 121; else if (value <= 1e-120) return 120; else if (value <= 1e-119) return 119; else if (value <= 1e-118) return 118; else if (value <= 1e-117) return 117; else if (value <= 1e-116) return 116; else if (value <= 1e-115) return 115; else if (value <= 1e-114) return 114; else if (value <= 1e-113) return 113; else if (value <= 1e-112) return 112; else if (value <= 1e-111) return 111; else if (value <= 1e-110) return 110; else if (value <= 1e-109) return 109; else if (value <= 1e-108) return 108; else if (value <= 1e-107) return 107; else if (value <= 1e-106) return 106; else if (value <= 1e-105) return 105; else if (value <= 1e-104) return 104; else if (value <= 1e-103) return 103; else if (value <= 1e-102) return 102; else if (value <= 1e-101) return 101; else if (value <= 1e-100) return 100; else if (value <= 1e-99) return 99; else if (value <= 1e-98) return 98; else if (value <= 1e-97) return 97; else if (value <= 1e-96) return 96; else if (value <= 1e-95) return 95; else if (value <= 1e-94) return 94; else if (value <= 1e-93) return 93; else if (value <= 1e-92) return 92; else if (value <= 1e-91) return 91; else if (value <= 1e-90) return 90; else if (value <= 1e-89) return 89; else if (value <= 1e-88) return 88; else if (value <= 1e-87) return 87; else if (value <= 1e-86) return 86; else if (value <= 1e-85) return 85; else if (value <= 1e-84) return 84; else if (value <= 1e-83) return 83; else if (value <= 1e-82) return 82; else if (value <= 1e-81) return 81; else if (value <= 1e-80) return 80; else if (value <= 1e-79) return 79; else if (value <= 1e-78) return 78; else if (value <= 1e-77) return 77; else if (value <= 1e-76) return 76; else if (value <= 1e-75) return 75; else if (value <= 1e-74) return 74; else if (value <= 1e-73) return 73; else if (value <= 1e-72) return 72; else if (value <= 1e-71) return 71; else if (value <= 1e-70) return 70; else if (value <= 1e-69) return 69; else if (value <= 1e-68) return 68; else if (value <= 1e-67) return 67; else if (value <= 1e-66) return 66; else if (value <= 1e-65) return 65; else if (value <= 1e-64) return 64; else if (value <= 1e-63) return 63; else if (value <= 1e-62) return 62; else if (value <= 1e-61) return 61; else if (value <= 1e-60) return 60; else if (value <= 1e-59) return 59; else if (value <= 1e-58) return 58; else if (value <= 1e-57) return 57; else if (value <= 1e-56) return 56; else if (value <= 1e-55) return 55; else if (value <= 1e-54) return 54; else if (value <= 1e-53) return 53; else if (value <= 1e-52) return 52; else if (value <= 1e-51) return 51; else if (value <= 1e-50) return 50; else if (value <= 1e-49) return 49; else if (value <= 1e-48) return 48; else if (value <= 1e-47) return 47; else if (value <= 1e-46) return 46; else if (value <= 1e-45) return 45; else if (value <= 1e-44) return 44; else if (value <= 1e-43) return 43; else if (value <= 1e-42) return 42; else if (value <= 1e-41) return 41; else if (value <= 1e-40) return 40; else if (value <= 1e-39) return 39; else if (value <= 1e-38) return 38; else if (value <= 1e-37) return 37; else if (value <= 1e-36) return 36; else if (value <= 1e-35) return 35; else if (value <= 1e-34) return 34; else if (value <= 1e-33) return 33; else if (value <= 1e-32) return 32; else if (value <= 1e-31) return 31; else if (value <= 1e-30) return 30; else if (value <= 1e-29) return 29; else if (value <= 1e-28) return 28; else if (value <= 1e-27) return 27; else if (value <= 1e-26) return 26; else if (value <= 1e-25) return 25; else if (value <= 1e-24) return 24; else if (value <= 1e-23) return 23; else if (value <= 1e-22) return 22; else if (value <= 1e-21) return 21; else if (value <= 1e-20) return 20; else if (value <= 1e-19) return 19; else if (value <= 1e-18) return 18; else if (value <= 1e-17) return 17; else if (value <= 1e-16) return 16; else if (value <= 1e-15) return 15; else if (value <= 1e-14) return 14; else if (value <= 1e-13) return 13; else if (value <= 1e-12) return 12; else if (value <= 1e-11) return 11; else if (value <= 1e-10) return 10; else if (value <= 1e-9) return 9; else if (value <= 1e-8) return 8; else if (value <= 1e-7) return 7; else if (value <= 1e-6) return 6; else if (value <= 1e-5) return 5; else if (value <= 1e-4) return 4; else if (value <= 1e-3) return 3; else if (value <= 1e-2) return 2; else if (value <= 1e-1) return 1; else if (value <= 1e-0) return 0; else return -1; } /** * Unit in the last place(ULP) for double * @param value Double number * @return ULP for a given double. */ public static double ulp(double value) { return Math.ulp(value); } /** * Unit in The Last Place - number of decimal digits before * @param value Double number * @return Positive number of digits N for ulp = 1e-{N+1}, * if ulp is > 1 then -1 is returned. * Returned proper value is always between -1 and +322. * If value is NaN then -2 is returned. */ public static int ulpDecimalDigitsBefore(double value) { if (Double.isNaN(value)) return -2; double u = ulp(value); return decimalDigitsBefore(u); } /** * Length of a number represented in a standard decimal format * @param value A given number * @return Length of a number represented in a standard decimal format * including decimal separator, excluding leading zeros (integer part), * excluding trailing zeros (fractional part) */ public static int decimalNumberLength(double value) { return DECIMAL_FORMAT.format(value).length(); } /** * Fractional part length of a number represented in a standard decimal format * @param value A given number * @return Fractional part length of a number represented in a standard decimal * format excluding decimal separator, excluding trailing zeros (fractional part) */ public static int fractionalPartLength(double value) { if (Double.isNaN(value)) return 0; if (Double.isInfinite(value)) return 0; if (ulpDecimalDigitsBefore(value) <= 0) return 0; String valueStr = DECIMAL_FORMAT.format(value); int dotPos = valueStr.indexOf('.'); if (dotPos >= 0) return valueStr.length() - 1 - dotPos; return 0; } /** * Intelligent rounding of a number within the decimal position of the ULP (Unit in the Last Place), * provided that the result is significantly shortened in the standard decimal notation. Examples: * 30.499999999999992 is rounded to 30.5, but 30.499999999999122 will not be rounded. Rounding is * made to the decimal position of the ULP minus 2 on condition that the resulted number is shortened * by at least 9 places. * @param value A given number * @return Returns an intelligently rounded number when the decimal position of ULP * is a minimum of 11 and when rounded to the position of ULP - 2, shortens * the number by a minimum of 9 places. Otherwise, returns original number. */ public static double lengthRound(double value) { if (Double.isNaN(value)) return value; if (Double.isInfinite(value)) return value; if (value == 0d || value == -1d || value == 1d || value == -2d || value == 2d || value == -3d || value == 3d) return value; if (value == -4d || value == 4d || value == -5d || value == 5d || value == -6d || value == 6d) return value; if (value == -7d || value == 7d || value == -8d || value == 8d || value == -9d || value == 9d) return value; if (value == -10d || value == 10d || value == -11d || value == 11d || value == -12d || value == 12d) return value; if (ulpDecimalDigitsBefore(value) < 6) return value; int decPartLen = fractionalPartLength(value); if (decPartLen < 11) return value; double valueRound = round(value, decPartLen - 2); int decPartLenRound = fractionalPartLength(valueRound); if (decPartLen - decPartLenRound >= 9) return valueRound; return value; } /** * Returns the first non-NaN value * * @param values List of values * @return Returns the first non-NaN value, if list is null * then returns Double.NaN, if list contains no elements * then returns Double.NaN. */ public static double coalesce(double[] values) { if (values == null) return Double.NaN; for (double v : values) { if (!Double.isNaN(v)) return v; if (mXparser.isCurrentCalculationCancelled()) return Double.NaN; } return Double.NaN; } /** * Check whether double value is almost integer. * @param x Number * @return True if double value is almost integer, otherwise false. * {@link BinaryRelations#DEFAULT_COMPARISON_EPSILON} * * @see BinaryRelations#DEFAULT_COMPARISON_EPSILON */ public static boolean isInteger(double x) { if (Double.isNaN(x)) return false; if (x == Double.POSITIVE_INFINITY) return false; if (x == Double.NEGATIVE_INFINITY) return false; if (x < 0) x = -x; double round = Math.round(x); return Math.abs(x - round) < BinaryRelations.DEFAULT_COMPARISON_EPSILON; } /** * Check whether two double values are almost equal. * @param a First number * @param b Second number * @return True if double values are almost equal, otherwise false. * {@link BinaryRelations#DEFAULT_COMPARISON_EPSILON} * * @see BinaryRelations#DEFAULT_COMPARISON_EPSILON */ public static boolean almostEqual(double a, double b) { if (Double.isNaN(a)) return false; if (Double.isNaN(b)) return false; if (a == b) return true; return Math.abs(a - b) <= BinaryRelations.DEFAULT_COMPARISON_EPSILON; } /** * Calculates function f(x0) (given as expression) assigning Argument x = x0; * * * @param f the expression * @param x the argument * @param x0 the argument value * * @return f.calculate() * * @see Expression */ public static double getFunctionValue(Expression f, Argument x, double x0) { x.setArgumentValue(x0); return f.calculate(); } /** * Returns array of double values of the function f(i) * calculated on the range: i = from to i = to by step = delta * * @param f Function expression * @param index Index argument * @param from 'from' value * @param to 'to' value * @param delta 'delta' step definition * @return Array of function values */ public static double[] getFunctionValues(Expression f, Argument index, double from, double to, double delta) { if (Double.isNaN(delta) || Double.isNaN(from) || Double.isNaN(to) || delta == 0) return null; int n = 0; double[] values; if (to >= from && delta > 0) { for (double i = from; i < to; i+=delta) n++; n++; values = new double[n]; int j = 0; for (double i = from; i < to; i+=delta) { values[j] = getFunctionValue(f, index, i); j++; } values[j] = getFunctionValue(f, index, to); } else if (to <= from && delta < 0) { for (double i = from; i > to; i+=delta) n++; n++; values = new double[n]; int j = 0; for (double i = from; i > to; i+=delta) { values[j] = getFunctionValue(f, index, i); j++; } values[j] = getFunctionValue(f, index, to); } else if (from == to) { n = 1; values = new double[n]; values[0] = getFunctionValue(f, index, from); } else values = null; return values; } }




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