Examples with MathContext java.math.MathContext used on opensource projects

Example 96 with MathContext

use of java.math.MathContext in project big-math by eobermuhlner.

the class BigDecimalMathExperimental method logUsingSqrt.

public static BigDecimal logUsingSqrt(BigDecimal x, MathContext mathContext, BiFunction<BigDecimal, MathContext, BigDecimal> logFunction) {
    MathContext mc = new MathContext(mathContext.getPrecision() + 4, mathContext.getRoundingMode());
    BigDecimal sqrtX = BigDecimalMath.sqrt(x, mc);
    BigDecimal result = logFunction.apply(sqrtX, mc).multiply(TWO, mc);
    return result.round(mathContext);
}

Example 97 with MathContext

use of java.math.MathContext in project big-math by eobermuhlner.

the class BigDecimalMathExperimental method exp.

public static BigDecimal exp(BigDecimal x, MathContext mathContext) {
    MathContext mc = new MathContext(mathContext.getPrecision() + 4, mathContext.getRoundingMode());
    BigDecimal result = ExpCalculator.INSTANCE.calculate(x, mc);
    return result.round(mathContext);
}

Example 98 with MathContext

use of java.math.MathContext in project big-math by eobermuhlner.

the class BigDecimalMathExperimental method logUsingNewtonFixPrecision.

public static BigDecimal logUsingNewtonFixPrecision(BigDecimal x, MathContext mathContext) {
    // https://en.wikipedia.org/wiki/Natural_logarithm in chapter 'High Precision'
    // y = y + 2 * (x-exp(y)) / (x+exp(y))
    MathContext mc = new MathContext(mathContext.getPrecision() + 4, mathContext.getRoundingMode());
    BigDecimal acceptableError = ONE.movePointLeft(mathContext.getPrecision() + 1);
    BigDecimal result = BigDecimal.valueOf(Math.log(x.doubleValue()));
    BigDecimal step;
    do {
        BigDecimal expY = BigDecimalMath.exp(result, mc);
        step = TWO.multiply(x.subtract(expY, mc), mc).divide(x.add(expY, mc), mc);
        result = result.add(step);
    } while (step.abs().compareTo(acceptableError) > 0);
    return result.round(mathContext);
}

Example 99 with MathContext

use of java.math.MathContext in project big-math by eobermuhlner.

the class BigDecimalMathExperimental method sqrtUsingHalley.

public static BigDecimal sqrtUsingHalley(BigDecimal x, MathContext mathContext) {
    switch(x.signum()) {
        case 0:
            return ZERO;
        case -1:
            throw new ArithmeticException("Illegal sqrt(x) for x < 0: x = " + x);
    }
    MathContext mc = new MathContext(mathContext.getPrecision() + 4, mathContext.getRoundingMode());
    BigDecimal acceptableError = ONE.movePointLeft(mathContext.getPrecision() + 1);
    BigDecimal threeX = x.multiply(THREE);
    BigDecimal result = BigDecimal.valueOf(Math.sqrt(x.doubleValue()));
    BigDecimal last;
    do {
        last = result;
        BigDecimal resultSquare = result.multiply(result);
        BigDecimal divisor = resultSquare.multiply(THREE).add(x);
        result = resultSquare.add(threeX).multiply(result).divide(divisor, mc);
    } while (result.subtract(last).abs().compareTo(acceptableError) > 0);
    return result.round(mathContext);
}

Example 100 with MathContext

use of java.math.MathContext in project big-math by eobermuhlner.

the class BigDecimalMathExperimental method sqrtUsingNewtonPrint.

// variations on sqrt()
public static BigDecimal sqrtUsingNewtonPrint(BigDecimal x, MathContext mathContext) {
    switch(x.signum()) {
        case 0:
            return ZERO;
        case -1:
            throw new ArithmeticException("Illegal sqrt(x) for x < 0: x = " + x);
    }
    MathContext mc = new MathContext(mathContext.getPrecision() + 4, mathContext.getRoundingMode());
    BigDecimal acceptableError = ONE.movePointLeft(mathContext.getPrecision() + 1);
    BigDecimal result = BigDecimal.valueOf(Math.sqrt(x.doubleValue()));
    BigDecimal last;
    do {
        last = result;
        result = x.divide(result, mc).add(last).divide(TWO, mc);
        System.out.printf("%5d, ", countSameCharacters(last.toPlainString(), result.toPlainString()));
    } while (result.subtract(last).abs().compareTo(acceptableError) > 0);
    return result.round(mathContext);
}