Example usage for java.math BigInteger multiply

List of usage examples for java.math BigInteger multiply

Introduction

In this page you can find the example usage for java.math BigInteger multiply.

Prototype

BigInteger multiply(long v) 

Source Link

Document

Package private methods used by BigDecimal code to multiply a BigInteger with a long.

Usage

From source file:com.ery.ertc.estorm.util.Bytes.java

/**
 * Iterate over keys within the passed range.
 *//*www.  ja v a  2 s. c  o  m*/
public static Iterable<byte[]> iterateOnSplits(final byte[] a, final byte[] b, boolean inclusive,
        final int num) {
    byte[] aPadded;
    byte[] bPadded;
    if (a.length < b.length) {
        aPadded = padTail(a, b.length - a.length);
        bPadded = b;
    } else if (b.length < a.length) {
        aPadded = a;
        bPadded = padTail(b, a.length - b.length);
    } else {
        aPadded = a;
        bPadded = b;
    }
    if (compareTo(aPadded, bPadded) >= 0) {
        throw new IllegalArgumentException("b <= a");
    }
    if (num <= 0) {
        throw new IllegalArgumentException("num cannot be < 0");
    }
    byte[] prependHeader = { 1, 0 };
    final BigInteger startBI = new BigInteger(add(prependHeader, aPadded));
    final BigInteger stopBI = new BigInteger(add(prependHeader, bPadded));
    BigInteger diffBI = stopBI.subtract(startBI);
    if (inclusive) {
        diffBI = diffBI.add(BigInteger.ONE);
    }
    final BigInteger splitsBI = BigInteger.valueOf(num + 1);
    if (diffBI.compareTo(splitsBI) < 0) {
        return null;
    }
    final BigInteger intervalBI;
    try {
        intervalBI = diffBI.divide(splitsBI);
    } catch (Exception e) {
        LOG.error("Exception caught during division", e);
        return null;
    }

    final Iterator<byte[]> iterator = new Iterator<byte[]>() {
        private int i = -1;

        @Override
        public boolean hasNext() {
            return i < num + 1;
        }

        @Override
        public byte[] next() {
            i++;
            if (i == 0)
                return a;
            if (i == num + 1)
                return b;

            BigInteger curBI = startBI.add(intervalBI.multiply(BigInteger.valueOf(i)));
            byte[] padded = curBI.toByteArray();
            if (padded[1] == 0)
                padded = tail(padded, padded.length - 2);
            else
                padded = tail(padded, padded.length - 1);
            return padded;
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }

    };

    return new Iterable<byte[]>() {
        @Override
        public Iterator<byte[]> iterator() {
            return iterator;
        }
    };
}

From source file:org.apache.kylin.common.util.Bytes.java

/**
 * Iterate over keys within the passed range.
 *///from w  w  w .  jav  a2 s . c om
public static Iterable<byte[]> iterateOnSplits(final byte[] a, final byte[] b, boolean inclusive,
        final int num) {
    byte[] aPadded;
    byte[] bPadded;
    if (a.length < b.length) {
        aPadded = padTail(a, b.length - a.length);
        bPadded = b;
    } else if (b.length < a.length) {
        aPadded = a;
        bPadded = padTail(b, a.length - b.length);
    } else {
        aPadded = a;
        bPadded = b;
    }
    if (compareTo(aPadded, bPadded) >= 0) {
        throw new IllegalArgumentException("b <= a");
    }
    if (num <= 0) {
        throw new IllegalArgumentException("num cannot be <= 0");
    }
    byte[] prependHeader = { 1, 0 };
    final BigInteger startBI = new BigInteger(add(prependHeader, aPadded));
    final BigInteger stopBI = new BigInteger(add(prependHeader, bPadded));
    BigInteger diffBI = stopBI.subtract(startBI);
    if (inclusive) {
        diffBI = diffBI.add(BigInteger.ONE);
    }
    final BigInteger splitsBI = BigInteger.valueOf(num + 1L);
    if (diffBI.compareTo(splitsBI) < 0) {
        return null;
    }
    final BigInteger intervalBI;
    try {
        intervalBI = diffBI.divide(splitsBI);
    } catch (Exception e) {
        LOG.error("Exception caught during division", e);
        return null;
    }

    final Iterator<byte[]> iterator = new Iterator<byte[]>() {
        private int i = -1;

        @Override
        public boolean hasNext() {
            return i < num + 1;
        }

        @Override
        public byte[] next() {
            i++;
            if (i == 0)
                return a;
            if (i == num + 1)
                return b;

            BigInteger curBI = startBI.add(intervalBI.multiply(BigInteger.valueOf(i)));
            byte[] padded = curBI.toByteArray();
            if (padded[1] == 0)
                padded = tail(padded, padded.length - 2);
            else
                padded = tail(padded, padded.length - 1);
            return padded;
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }

    };

    return new Iterable<byte[]>() {
        @Override
        public Iterator<byte[]> iterator() {
            return iterator;
        }
    };
}

From source file:org.apache.hadoop.hbase.util.Bytes.java

/**
 * Iterate over keys within the passed range.
 *///w w w.j a v a2s  .c om
public static Iterable<byte[]> iterateOnSplits(final byte[] a, final byte[] b, boolean inclusive,
        final int num) {
    byte[] aPadded;
    byte[] bPadded;
    if (a.length < b.length) {
        aPadded = padTail(a, b.length - a.length);
        bPadded = b;
    } else if (b.length < a.length) {
        aPadded = a;
        bPadded = padTail(b, a.length - b.length);
    } else {
        aPadded = a;
        bPadded = b;
    }
    if (compareTo(aPadded, bPadded) >= 0) {
        throw new IllegalArgumentException("b <= a");
    }
    if (num <= 0) {
        throw new IllegalArgumentException("num cannot be <= 0");
    }
    byte[] prependHeader = { 1, 0 };
    final BigInteger startBI = new BigInteger(add(prependHeader, aPadded));
    final BigInteger stopBI = new BigInteger(add(prependHeader, bPadded));
    BigInteger diffBI = stopBI.subtract(startBI);
    if (inclusive) {
        diffBI = diffBI.add(BigInteger.ONE);
    }
    final BigInteger splitsBI = BigInteger.valueOf(num + 1);
    if (diffBI.compareTo(splitsBI) < 0) {
        return null;
    }
    final BigInteger intervalBI;
    try {
        intervalBI = diffBI.divide(splitsBI);
    } catch (Exception e) {
        LOG.error("Exception caught during division", e);
        return null;
    }

    final Iterator<byte[]> iterator = new Iterator<byte[]>() {
        private int i = -1;

        @Override
        public boolean hasNext() {
            return i < num + 1;
        }

        @Override
        public byte[] next() {
            i++;
            if (i == 0)
                return a;
            if (i == num + 1)
                return b;

            BigInteger curBI = startBI.add(intervalBI.multiply(BigInteger.valueOf(i)));
            byte[] padded = curBI.toByteArray();
            if (padded[1] == 0)
                padded = tail(padded, padded.length - 2);
            else
                padded = tail(padded, padded.length - 1);
            return padded;
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }

    };

    return new Iterable<byte[]>() {
        @Override
        public Iterator<byte[]> iterator() {
            return iterator;
        }
    };
}

From source file:org.jmangos.realm.network.packet.auth.client.CMD_AUTH_LOGON_CHALLENGE.java

@Override
protected void readImpl() throws BufferUnderflowException, RuntimeException {

    readC();//  w  w w . j  a  va  2s .  com
    if (readC() == WoWAuthResponse.WOW_SUCCESS.getMessageId()) {
        final SecureRandom random = new SecureRandom();
        MessageDigest sha = null;
        try {
            sha = MessageDigest.getInstance("SHA-1");
        } catch (final NoSuchAlgorithmException e) {
            e.printStackTrace();
            return;
        }
        final BigInteger k = new BigInteger("3");
        final byte[] Bb = readB(32);
        final BigInteger g = new BigInteger(readB(readC()));
        final byte[] Nb = readB(readC());
        final byte[] saltb = readB(32);
        /* byte[] unk3 = */readB(16);
        readC();
        ArrayUtils.reverse(Bb);
        final BigInteger B = new BigInteger(1, Bb);
        ArrayUtils.reverse(Bb);
        ArrayUtils.reverse(Nb);
        final BigInteger N = new BigInteger(1, Nb);
        ArrayUtils.reverse(Nb);
        final BigInteger a = new BigInteger(1, random.generateSeed(19));

        final byte[] passhash = sha.digest(this.config.AUTH_LOGIN.toUpperCase().concat(":")
                .concat(this.config.AUTH_PASSWORD.toUpperCase()).getBytes(Charset.forName("UTF-8")));
        sha.update(saltb);
        sha.update(passhash);

        final byte[] xhash = sha.digest();
        ArrayUtils.reverse(xhash);
        final BigInteger x = new BigInteger(1, xhash);
        logger.debug("x:" + x.toString(16).toUpperCase());
        final BigInteger v = g.modPow(x, N);
        logger.debug("v:" + v.toString(16).toUpperCase());
        final BigInteger A = g.modPow(a, N);
        logger.debug("A:" + A.toString(16).toUpperCase());
        logger.debug("B:" + B.toString(16).toUpperCase());
        this.ahash = A.toByteArray();
        ArrayUtils.reverse(this.ahash);
        sha.update(this.ahash);
        sha.update(Bb);
        final byte[] hashu = sha.digest();
        ArrayUtils.reverse(hashu);
        final BigInteger u = new BigInteger(1, hashu);
        logger.debug("u:" + u.toString(16).toUpperCase());
        final BigInteger S = (B.subtract(k.multiply(g.modPow(x, N)))).modPow(a.add(u.multiply(x)), N);

        final byte[] full_S = S.toByteArray();
        ArrayUtils.reverse(full_S);
        logger.debug("t:" + StringUtils.toHexString(full_S));
        final byte[] s1_hash = new byte[16];
        final byte[] s2_hash = new byte[16];
        for (int i = 0; i < 16; i++) {
            s1_hash[i] = full_S[i * 2];
            s2_hash[i] = full_S[(i * 2) + 1];
        }
        final byte[] t1 = sha.digest(s1_hash);
        final byte[] t2 = sha.digest(s2_hash);
        final byte[] vK = new byte[40];
        for (int i = 0; i < 20; i++) {
            vK[i * 2] = t1[i];
            vK[(i * 2) + 1] = t2[i];
        }

        byte[] hash = new byte[20];
        logger.debug("N:" + N.toString(16).toUpperCase());
        hash = sha.digest(Nb);

        logger.debug("hash:" + new BigInteger(1, hash).toString(16).toUpperCase());

        byte[] gH = new byte[20];
        sha.update(g.toByteArray());
        gH = sha.digest();
        for (int i = 0; i < 20; ++i) {
            hash[i] ^= gH[i];
        }

        byte[] t4 = new byte[20];
        t4 = sha.digest(this.config.AUTH_LOGIN.toUpperCase().getBytes(Charset.forName("UTF-8")));

        sha.update(hash);
        logger.debug("hash:" + StringUtils.toHexString(hash));
        sha.update(t4);
        logger.debug("t4:" + StringUtils.toHexString(t4));
        sha.update(saltb);
        logger.debug("saltb:" + StringUtils.toHexString(saltb));
        sha.update(this.ahash);
        logger.debug("ahash:" + StringUtils.toHexString(this.ahash));
        sha.update(Bb);
        logger.debug("Bb:" + StringUtils.toHexString(Bb));
        sha.update(vK);
        logger.debug("vK:" + StringUtils.toHexString(vK));
        this.m1 = sha.digest();

        sha.update(this.ahash);
        sha.update(this.m1);
        sha.update(vK);
        logger.debug("m1 value" + StringUtils.toHexString(this.m1));
        @SuppressWarnings("unused")
        final byte[] m2 = sha.digest();

        final ChannelPipeline pipeline = getClient().getChannel().getPipeline();
        ((RealmToAuthChannelHandler) pipeline.getLast()).setSeed(vK);

    } else {
        getChannel().getPipeline().remove("handler");
        getChannel().getPipeline().remove("eventlog");
        getChannel().getPipeline().remove("executor");
        getChannel().close();
        getChannel().getFactory().releaseExternalResources();
    }
}

From source file:org.nd4j.linalg.util.BigDecimalMath.java

/**
 * Trigonometric cosine.//from  w ww .  j a v  a  2 s  .c  om
 *
 * @param x The argument in radians.
 * @return cos(x) in the range -1 to 1.
 */
static public BigDecimal cos(final BigDecimal x) {
    if (x.compareTo(BigDecimal.ZERO) < 0) {
        return cos(x.negate());
    } else if (x.compareTo(BigDecimal.ZERO) == 0) {
        return BigDecimal.ONE;
    } else {
        /* reduce modulo 2pi
         */
        BigDecimal res = mod2pi(x);
        double errpi = 0.5 * Math.abs(x.ulp().doubleValue());
        int val = +err2prec(FastMath.PI, errpi);
        MathContext mc = new MathContext(val);
        BigDecimal p = pi(mc);
        mc = new MathContext(x.precision());
        if (res.compareTo(p) > 0) {
            /* pi<x<=2pi: cos(x)= - cos(x-pi)
             */
            return cos(subtractRound(res, p)).negate();
        } else if (res.multiply(new BigDecimal("2")).compareTo(p) > 0) {
            /* pi/2<x<=pi: cos(x)= -cos(pi-x)
             */
            return cos(subtractRound(p, res)).negate();
        } else {
            /* for the range 0<=x<Pi/2 one could use cos(2x)= 1-2*sin^2(x)
             * to split this further, or use the cos up to pi/4 and the sine higher up.
            throw new ProviderException("Unimplemented cosine ") ;
             */
            if (res.multiply(new BigDecimal("4")).compareTo(p) > 0) {
                /* x>pi/4: cos(x) = sin(pi/2-x)
                 */
                return sin(subtractRound(p.divide(new BigDecimal("2")), res));
            } else {
                /* Simple Taylor expansion, sum_{i=0..infinity} (-1)^(..)res^(2i)/(2i)! */
                BigDecimal resul = BigDecimal.ONE;
                /* x^i */
                BigDecimal xpowi = BigDecimal.ONE;
                /* 2i factorial */
                BigInteger ifac = BigInteger.ONE;
                /* The absolute error in the result is the error in x^2/2 which is x times the error in x.
                 */
                double xUlpDbl = 0.5 * res.ulp().doubleValue() * res.doubleValue();
                /* The error in the result is set by the error in x^2/2 itself, xUlpDbl.
                 * We need at most k terms to push x^(2k+1)/(2k+1)! below this value.
                 * x^(2k) < xUlpDbl; (2k)*log(x) < log(xUlpDbl);
                 */
                int k = (int) (Math.log(xUlpDbl) / Math.log(res.doubleValue())) / 2;
                MathContext mcTay = new MathContext(err2prec(1., xUlpDbl / k));
                for (int i = 1;; i++) {
                    /* TBD: at which precision will 2*i-1 or 2*i overflow?
                     */
                    ifac = ifac.multiply(new BigInteger("" + (2 * i - 1)));
                    ifac = ifac.multiply(new BigInteger("" + (2 * i)));
                    xpowi = xpowi.multiply(res).multiply(res).negate();
                    BigDecimal corr = xpowi.divide(new BigDecimal(ifac), mcTay);
                    resul = resul.add(corr);
                    if (corr.abs().doubleValue() < 0.5 * xUlpDbl) {
                        break;
                    }
                }
                /* The error in the result is governed by the error in x itself.
                 */
                mc = new MathContext(err2prec(resul.doubleValue(), xUlpDbl));
                return resul.round(mc);
            }
        }
    }
}

From source file:org.nd4j.linalg.util.BigDecimalMath.java

/**
 * The hyperbolic sine./*from   w  ww  . ja  v  a 2 s.  c  o m*/
 *
 * @param x the argument.
 * @return the sinh(x) = (exp(x)-exp(-x))/2 .
 */
static public BigDecimal sinh(final BigDecimal x) {
    if (x.compareTo(BigDecimal.ZERO) < 0) {
        return sinh(x.negate()).negate();
    } else if (x.compareTo(BigDecimal.ZERO) == 0) {
        return BigDecimal.ZERO;
    } else {
        if (x.doubleValue() > 2.4) {
            /* Move closer to zero with sinh(2x)= 2*sinh(x)*cosh(x).
             */
            BigDecimal two = new BigDecimal(2);
            BigDecimal xhalf = x.divide(two);

            BigDecimal resul = sinh(xhalf).multiply(cosh(xhalf)).multiply(two);
            /* The error in the result is set by the error in x itself.
             * The first derivative of sinh(x) is cosh(x), so the absolute error
             * in the result is cosh(x)*errx, and the relative error is coth(x)*errx = errx/tanh(x)
             */

            double eps = Math.tanh(x.doubleValue());
            MathContext mc = new MathContext(err2prec(0.5 * x.ulp().doubleValue() / eps));

            return resul.round(mc);

        } else {
            BigDecimal xhighpr = scalePrec(x, 2);
            /* Simple Taylor expansion, sum_{i=0..infinity} x^(2i+1)/(2i+1)! */
            BigDecimal resul = xhighpr;
            /* x^i */
            BigDecimal xpowi = xhighpr;
            /* 2i+1 factorial */
            BigInteger ifac = BigInteger.ONE;
            /* The error in the result is set by the error in x itself.
             */

            double xUlpDbl = x.ulp().doubleValue();
            /* The error in the result is set by the error in x itself.
             * We need at most k terms to squeeze x^(2k+1)/(2k+1)! below this value.
             * x^(2k+1) < x.ulp; (2k+1)*log10(x) < -x.precision; 2k*log10(x)< -x.precision;
             * 2k*(-log10(x)) > x.precision; 2k*log10(1/x) > x.precision
             */

            int k = (int) (x.precision() / Math.log10(1.0 / xhighpr.doubleValue())) / 2;
            MathContext mcTay = new MathContext(err2prec(x.doubleValue(), xUlpDbl / k));

            for (int i = 1;; i++) {
                /* TBD: at which precision will 2*i or 2*i+1 overflow?
                 */
                ifac = ifac.multiply(new BigInteger("" + (2 * i)));
                ifac = ifac.multiply(new BigInteger("" + (2 * i + 1)));
                xpowi = xpowi.multiply(xhighpr).multiply(xhighpr);
                BigDecimal corr = xpowi.divide(new BigDecimal(ifac), mcTay);
                resul = resul.add(corr);

                if (corr.abs().doubleValue() < 0.5 * xUlpDbl) {
                    break;
                }

            } /* The error in the result is set by the error in x itself.
              */
            MathContext mc = new MathContext(x.precision());

            return resul.round(mc);

        }
    }
}

From source file:org.nd4j.linalg.util.BigDecimalMath.java

/**
 * Trigonometric sine.//from   w  w  w  .  ja  v a2 s  .  c  o  m
 *
 * @param x The argument in radians.
 * @return sin(x) in the range -1 to 1.
 */
static public BigDecimal sin(final BigDecimal x) {
    if (x.compareTo(BigDecimal.ZERO) < 0) {
        return sin(x.negate()).negate();
    } else if (x.compareTo(BigDecimal.ZERO) == 0) {
        return BigDecimal.ZERO;
    } else {
        /* reduce modulo 2pi
         */
        BigDecimal res = mod2pi(x);
        double errpi = 0.5 * Math.abs(x.ulp().doubleValue());
        int val = 2 + err2prec(FastMath.PI, errpi);
        MathContext mc = new MathContext(val);
        BigDecimal p = pi(mc);
        mc = new MathContext(x.precision());
        if (res.compareTo(p) > 0) {
            /* pi<x<=2pi: sin(x)= - sin(x-pi)
             */
            return sin(subtractRound(res, p)).negate();
        } else if (res.multiply(new BigDecimal("2")).compareTo(p) > 0) {
            /* pi/2<x<=pi: sin(x)= sin(pi-x)
             */
            return sin(subtractRound(p, res));
        } else {
            /* for the range 0<=x<Pi/2 one could use sin(2x)=2sin(x)cos(x)
             * to split this further. Here, use the sine up to pi/4 and the cosine higher up.
             */
            if (res.multiply(new BigDecimal("4")).compareTo(p) > 0) {
                /* x>pi/4: sin(x) = cos(pi/2-x)
                 */
                return cos(subtractRound(p.divide(new BigDecimal("2")), res));
            } else {
                /* Simple Taylor expansion, sum_{i=1..infinity} (-1)^(..)res^(2i+1)/(2i+1)! */
                BigDecimal resul = res;
                /* x^i */
                BigDecimal xpowi = res;
                /* 2i+1 factorial */
                BigInteger ifac = BigInteger.ONE;
                /* The error in the result is set by the error in x itself.
                 */
                double xUlpDbl = res.ulp().doubleValue();
                /* The error in the result is set by the error in x itself.
                 * We need at most k terms to squeeze x^(2k+1)/(2k+1)! below this value.
                 * x^(2k+1) < x.ulp; (2k+1)*log10(x) < -x.precision; 2k*log10(x)< -x.precision;
                 * 2k*(-log10(x)) > x.precision; 2k*log10(1/x) > x.precision
                 */
                int k = (int) (res.precision() / Math.log10(1.0 / res.doubleValue())) / 2;
                MathContext mcTay = new MathContext(err2prec(res.doubleValue(), xUlpDbl / k));
                for (int i = 1;; i++) {
                    /* TBD: at which precision will 2*i or 2*i+1 overflow?
                     */
                    ifac = ifac.multiply(new BigInteger("" + (2 * i)));
                    ifac = ifac.multiply(new BigInteger("" + (2 * i + 1)));
                    xpowi = xpowi.multiply(res).multiply(res).negate();
                    BigDecimal corr = xpowi.divide(new BigDecimal(ifac), mcTay);
                    resul = resul.add(corr);
                    if (corr.abs().doubleValue() < 0.5 * xUlpDbl) {
                        break;
                    }
                }
                /* The error in the result is set by the error in x itself.
                 */
                mc = new MathContext(res.precision());
                return resul.round(mc);
            }
        }
    } /* sin */
}

From source file:com.udojava.evalex.Expression.java

/**
 * Creates a new expression instance from an expression string with a given
 * default match context./*from   w w  w . ja v  a 2  s.c o m*/
 *
 * @param expression The expression. E.g. <code>"2.4*sin(3)/(2-4)"</code> or
 *                   <code>"sin(y)>0 & max(z, 3)>3"</code>
 */
public Expression(String expression, LinkedList<String> hist, Variables vars) {
    this.history = hist;
    this.expression = expression;

    mainVars = vars;

    addOperator(new Operator("+", 20, true, "Addition") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            if (v1.type == ValueType.ARRAY) {
                MyComplex vo = new MyComplex(v1.list);
                vo.list.add(v2);
                return vo;
            }
            return v1.add(v2);
        }
    });

    addOperator(new Operator("-", 20, true, "Subtraction") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            if (v1.type == ValueType.ARRAY) {
                MyComplex vo = new MyComplex(v1.list);
                vo.list.removeIf(o -> o.equals(v2));
                return vo;
            }
            return v1.subtract(v2);
        }
    });
    addOperator(new Operator("*", 30, true, "Real number multiplication") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            return v1.multiply(v2);
        }
    });
    addOperator(new Operator("/", 30, true, "Real number division") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            return v1.divide(v2);
        }
    });
    addOperator(new Operator("%", 30, true, "Remainder of integer division") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            double r = v1.real % v2.real;
            return new MyComplex(r);
        }
    });
    addOperator(
            new Operator("^", 40, false, "Exponentation. See: https://en.wikipedia.org/wiki/Exponentiation") {
                @Override
                public MyComplex eval(MyComplex v1, MyComplex v2) {
                    return v1.pow(v2);
                }
            });
    addOperator(new Operator("&&", 4, false, "Logical AND. Evaluates to 1 if both operands are not 0") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            boolean b1 = (v1.real == 0.0 && v2.real == 0.0);
            return new MyComplex(b1 ? 1 : 0);
        }
    });

    addOperator(new Operator("||", 2, false, "Logical OR. Evaluates to 0 if both operands are 0") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            boolean b1 = (v1.real == 0.0 && v2.real == 0.0);
            return new MyComplex(b1 ? 0 : 1);
        }
    });

    addOperator(new Operator(">", 10, false,
            "Greater than. See: See: https://en.wikipedia.org/wiki/Inequality_(mathematics)") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            if (v1.type == ValueType.REAL && v2.type == ValueType.REAL) {
                return new MyComplex(v1.real > v2.real ? 1 : 0);
            } else {
                return new MyComplex(v1.abs() > v2.abs() ? 1 : 0);
            }
        }
    });

    addOperator(new Operator(">=", 10, false, "Greater or equal") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            if (v1.type == ValueType.REAL && v2.type == ValueType.REAL) {
                return new MyComplex(v1.real >= v2.real ? 1 : 0);
            } else {
                return new MyComplex(v1.abs() >= v2.abs() ? 1 : 0);
            }
        }
    });

    addOperator(new Operator("<", 10, false,
            "Less than. See: https://en.wikipedia.org/wiki/Inequality_(mathematics)") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            if (v1.type == ValueType.REAL && v2.type == ValueType.REAL) {
                return new MyComplex(v1.real < v2.real ? 1 : 0);
            } else {
                return new MyComplex(v1.abs() < v2.abs() ? 1 : 0);
            }
        }
    });

    addOperator(new Operator("<=", 10, false, "less or equal") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            if (v1.type == ValueType.REAL && v2.type == ValueType.REAL) {
                return new MyComplex(v1.real <= v2.real ? 1 : 0);
            } else {
                return new MyComplex(v1.abs() <= v2.abs() ? 1 : 0);
            }
        }
    });

    addOperator(new Operator("->", 7, false, "Set variable v to new value ") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            if (v1 instanceof PitDecimal) {
                PitDecimal target = (PitDecimal) v1;
                String s = target.getVarToken();
                setVariable(s, v2);
                return v2;
            }
            throw new ExpressionException("LHS not variable");
        }
    });

    addOperator(new Operator("=", 7, false, "Equality") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            if (v1.type == ValueType.REAL && v2.type == ValueType.REAL) {
                return new MyComplex(v1.real == v2.real ? 1 : 0);
            } else {
                return new MyComplex(v1.abs() == v2.abs() ? 1 : 0);
            }
        }
    });

    addOperator(new Operator("!=", 7, false,
            "Inequality. See: https://en.wikipedia.org/wiki/Inequality_(mathematics)") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            if (v1.type == ValueType.REAL && v2.type == ValueType.REAL) {
                return new MyComplex(v1.real != v2.real ? 1 : 0);
            } else {
                return new MyComplex(v1.abs() != v2.abs() ? 1 : 0);
            }
        }
    });
    addOperator(
            new Operator("or", 7, false, "Bitwise OR. See: https://en.wikipedia.org/wiki/Logical_disjunction") {
                @Override
                public MyComplex eval(MyComplex v1, MyComplex v2) {
                    return new MyComplex((long) v1.real | (long) v2.real);
                }
            });
    addOperator(new Operator("and", 7, false,
            "Bitwise AND. See: https://en.wikipedia.org/wiki/Logical_conjunction") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            return new MyComplex((long) v1.real & (long) v2.real);
        }
    });
    addOperator(new Operator("xor", 7, false, "Bitwise XOR, See: https://en.wikipedia.org/wiki/Exclusive_or") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            return new MyComplex((long) v1.real ^ (long) v2.real);
        }
    });

    addOperator(new Operator("!", 50, true, "Factorial. See https://en.wikipedia.org/wiki/Factorial") {
        public BigInteger factorial(long n) {
            BigInteger factorial = BigInteger.ONE;
            for (long i = 1; i <= n; i++) {
                factorial = factorial.multiply(BigInteger.valueOf(i));
            }
            return factorial;
        }

        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            BigInteger fact = factorial((long) v1.real);
            return new MyComplex(fact, BigInteger.ZERO);
        }
    });

    addOperator(new Operator("~", 8, false, "Bitwise negation") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            BigInteger bi = v2.toBigIntegerReal();
            int c = bi.bitLength();
            if (c == 0) {
                return new MyComplex(1);
            }
            for (int s = 0; s < c; s++) {
                bi = bi.flipBit(s);
            }
            return new MyComplex(bi);
        }
    });

    addOperator(new Operator("shl", 8, false, "Left Bit shift") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            return new MyComplex((long) v1.real << (long) v2.real);
        }
    });

    addOperator(new Operator("shr", 8, false, "Right bit shift") {
        @Override
        public MyComplex eval(MyComplex v1, MyComplex v2) {
            return new MyComplex((long) v1.real >>> (long) v2.real);
        }
    });

    addFunction(new Function("NOT", 1, "evaluates to 0 if argument != 0") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            boolean zero = parameters.get(0).abs() == 0;
            return new MyComplex(zero ? 1 : 0);
        }
    });

    addFunction(new Function("RND", 2, "Give random number in the range between first and second argument") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double low = parameters.get(0).real;
            double high = parameters.get(1).real;
            return new MyComplex(low + Math.random() * (high - low));
        }
    });

    MersenneTwister mers = new MersenneTwister(System.nanoTime());

    addFunction(new Function("MRS", 0, "Mersenne twister random generator") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return new MyComplex(mers.nextDouble());
        }
    });

    addFunction(new Function("BIN", 2, "Binomial Coefficient 'n choose k'") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            int n = (int) parameters.get(0).real;
            int k = (int) parameters.get(1).real;
            double d = CombinatoricsUtils.binomialCoefficientDouble(n, k);
            return new MyComplex(d);
        }
    });
    addFunction(new Function("STIR", 2,
            "Stirling number of 2nd kind: http://mathworld.wolfram.com/StirlingNumberoftheSecondKind.html") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            int n = (int) parameters.get(0).real;
            int k = (int) parameters.get(1).real;
            double d = CombinatoricsUtils.stirlingS2(n, k);
            return new MyComplex(d);
        }
    });

    addFunction(new Function("SIN", 1, "Sine function") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).sin();
        }
    });
    addFunction(new Function("COS", 1, "Cosine function") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).cos();
        }
    });
    addFunction(new Function("TAN", 1, "Tangent") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).tan();
        }
    });
    addFunction(new Function("ASIN", 1, "Reverse Sine") { // added by av
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).asin();
        }
    });
    addFunction(new Function("ACOS", 1, "Reverse Cosine") { // added by av
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).acos();
        }
    });
    addFunction(new Function("ATAN", 1, "Reverse Tangent") { // added by av
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).atan();
        }
    });
    addFunction(new Function("SINH", 1, "Hyperbolic Sine") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).sinh();
        }
    });
    addFunction(new Function("COSH", 1, "Hyperbolic Cosine") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).cosh();
        }
    });
    addFunction(new Function("TANH", 1, "Hyperbolic Tangent") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).tanh();
        }
    });
    addFunction(new Function("RAD", 1, "Transform degree to radian") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double d = Math.toRadians(parameters.get(0).real);
            return new MyComplex(d);
        }
    });
    addFunction(new Function("DEG", 1, "Transform radian to degree") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double d = Math.toDegrees(parameters.get(0).real);
            return new MyComplex(d);
        }
    });
    addFunction(new Function("MAX", -1, "Find the biggest value in a list") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            MyComplex save = new MyComplex(Double.MIN_VALUE);
            if (parameters.size() == 0) {
                throw new ExpressionException("MAX requires at least one parameter");
            }
            //                if (parameters.get(0).type == ValueType.ARRAY)
            //                    parameters = parameters.get(0).list;
            if (parameters.get(0).type == ValueType.COMPLEX) {
                for (MyComplex parameter : parameters) {
                    if (parameter.abs() > save.abs()) {
                        save = parameter;
                    }
                }
                save.type = ValueType.COMPLEX;
            } else {
                for (MyComplex parameter : parameters) {
                    if (parameter.real > save.real) {
                        save = parameter;
                    }
                }
                save.type = ValueType.REAL;
            }
            return save;
        }
    });
    ///////////////////////////////////////////////////////
    addFunction(new Function("IF", 3, "Conditional: give param3 if param1 is 0, otherwise param2") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            if (parameters.get(0).real == 0.0) {
                return parameters.get(2);
            }
            return parameters.get(1);
        }
    });

    addFunction(new Function("PERC", 2, "Get param1 percent of param2") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).divide(new MyComplex(100)).multiply(parameters.get(1));
        }
    });

    addFunction(new Function("PER", 2, "How many percent is param1 of param2") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return parameters.get(0).multiply(new MyComplex(100)).divide(parameters.get(1));
        }
    });

    addFunction(new Function("H", 1, "Evaluate _history element") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            int i = (int) parameters.get(0).real;
            Expression ex = new Expression(history.get(i), history, mainVars);
            return ex.eval();
        }
    });

    addFunction(new Function("MERS", 1, "Calculate Mersenne Number") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            MyComplex p = parameters.get(0);
            return new MyComplex(2).pow(p).subtract(new MyComplex(1));
        }
    });

    addFunction(new Function("GCD", 2, "Find greatest common divisor of 2 values") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double a = parameters.get(0).real;
            double b = parameters.get(1).real;
            long r = ArithmeticUtils.gcd((long) a, (long) b);
            return new MyComplex(r);
        }
    });
    addFunction(new Function("LCM", 2, "Find least common multiple of 2 values") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double a = parameters.get(0).real;
            double b = parameters.get(1).real;
            long r = ArithmeticUtils.lcm((long) a, (long) b);
            return new MyComplex(r);
        }
    });
    addFunction(new Function("AMEAN", -1, "Arithmetic mean of a set of values") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            if (parameters.size() == 0) {
                throw new ExpressionException("MEAN requires at least one parameter");
            }
            Mean m = new Mean();
            double[] d = MyComplex.getRealArray(parameters);
            double d2 = m.evaluate(d);
            return new MyComplex(d2);
        }
    });
    //        addFunction(new Function("BYT", -1,
    //                "Value from sequence of bytes")
    //        {
    //            @Override
    //            public MyComplex eval (List<MyComplex> parameters)
    //            {
    //                if (parameters.size() == 0)
    //                {
    //                    return MyComplex.ZERO;
    //                }
    //                BigInteger res = BigInteger.ZERO;
    //                for (MyComplex parameter : parameters)
    //                {
    //                    if (parameter.intValue() < 0 || parameter.intValue() > 255)
    //                    {
    //                        throw new ExpressionException("not a byte value");
    //                    }
    //                    res = res.shiftLeft(8);
    //                    res = res.or(parameter.toBigInteger());
    //                }
    //                return new MyComplex(res, BigInteger.ZERO);
    //            }
    //        });
    addFunction(new Function("SEQ", 3, "Generate Sequence p1=start, p2=step, p3=count") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double start = parameters.get(0).real;
            ArrayList<MyComplex> arr = new ArrayList<>();
            for (int s = 0; s < (int) (parameters.get(2).real); s++) {
                arr.add(new MyComplex(start));
                start += parameters.get(1).real;
            }
            return new MyComplex(arr);
        }
    });

    addFunction(new Function("PROD", -1, "Product of real values") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            Product p = new Product();
            double[] d = MyComplex.getRealArray(parameters);
            return new MyComplex(p.evaluate(d));
        }
    });

    addFunction(new Function("SUM", -1, "Sum of values") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            Sum p = new Sum();
            double[] d = MyComplex.getRealArray(parameters);
            return new MyComplex(p.evaluate(d));
        }
    });

    addFunction(new Function("ANG", 1, "Angle phi of complex number in radians") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double b = parameters.get(0).angle();
            return new MyComplex(b);
        }
    });

    addFunction(new Function("IM", 1, "Get imaginary part") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return new MyComplex(parameters.get(0).imaginary);
        }
    });

    addFunction(new Function("RE", 1, "Get real part") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return new MyComplex(parameters.get(0).real);
        }
    });

    addFunction(new Function("POL", 2, "Make complex number from polar coords. angle is first arg") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double angle = parameters.get(0).real;
            double len = parameters.get(1).real;
            Complex c = ComplexUtils.polar2Complex(len, angle);
            return new MyComplex(c);
        }
    });

    addFunction(new Function("GMEAN", -1, "Geometric mean of a set of values") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            if (parameters.size() == 0) {
                throw new ExpressionException("MEAN requires at least one parameter");
            }
            GeometricMean m = new GeometricMean();
            double[] d = MyComplex.getRealArray(parameters);
            double d2 = m.evaluate(d);
            return new MyComplex(d2);
        }
    });

    addFunction(new Function("HMEAN", -1, "Harmonic mean of a set of values") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            if (parameters.size() == 0) {
                throw new ExpressionException("MEAN requires at least one parameter");
            }
            MyComplex res = new MyComplex(0);
            int num = 0;
            for (MyComplex parameter : parameters) {
                res = res.add(new MyComplex(1).divide(parameter));
                num++;
            }
            res = new MyComplex(res.abs());
            return new MyComplex(num).divide(res);
        }
    });

    addFunction(new Function("VAR", -1, "Variance of a set of values") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            if (parameters.size() == 0) {
                throw new ExpressionException("MEAN requires at least one parameter");
            }
            double[] arr = new double[parameters.size()];
            for (int s = 0; s < parameters.size(); s++) {
                arr[s] = parameters.get(s).real;
            }
            return new MyComplex(variance(arr));
        }
    });

    addFunction(new Function("NPR", 1, "Next prime number greater or equal the argument") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return new MyComplex(nextPrime((int) parameters.get(0).real));
        }
    });

    addFunction(new Function("NSWP", 1, "Swap nibbles") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            BigInteger bi = parameters.get(0).toBigIntegerReal();
            String s = bi.toString(16);
            s = new StringBuilder(s).reverse().toString();
            return new MyComplex(new BigInteger(s, 16), BigInteger.ZERO);
        }
    });

    addFunction(new Function("BSWP", 1, "Swap bytes") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            BigInteger bi = parameters.get(0).toBigIntegerReal();
            String s = bi.toString(16);
            while (s.length() % 4 != 0) {
                s = s + "0";
            }
            if (bi.intValue() < 256) {
                s = "00" + s;
            }
            s = Misc.reverseHex(s);
            return new MyComplex(new BigInteger(s, 16), BigInteger.ZERO);
        }
    });

    addFunction(new Function("PYT", 2,
            "Pythagoras's result = sqrt(param1^2+param2^2) https://en.wikipedia.org/wiki/Pythagorean_theorem") {
        @Override
        public MyComplex eval(List<MyComplex> par) {
            double a = par.get(0).real;
            double b = par.get(1).real;
            return new MyComplex(Math.sqrt(a * a + b * b));
        }
    });

    addFunction(new Function("FIB", 1, "Fibonacci number") {
        // --Commented out by Inspection (2/19/2017 7:46 PM):private final Operator exp = operators.get("^");

        @Override
        public MyComplex eval(List<MyComplex> par) {
            return Misc.iterativeFibonacci((int) par.get(0).real);
        }
    });

    ///////////////////////////////////////////////

    addFunction(new Function("MIN", -1, "Find the smallest in a list of values") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            MyComplex save = new MyComplex(Double.MAX_VALUE);
            if (parameters.size() == 0) {
                throw new ExpressionException("MAX requires at least one parameter");
            }
            if (parameters.get(0).type == ValueType.COMPLEX) {
                for (MyComplex parameter : parameters) {
                    if (parameter.abs() < save.abs()) {
                        save = parameter;
                    }
                }
                save.type = ValueType.COMPLEX;
            } else {
                for (MyComplex parameter : parameters) {
                    if (parameter.real < save.real) {
                        save = parameter;
                    }
                }
                save.type = ValueType.REAL;
            }
            return save;
        }
    });
    addFunction(new Function("ABS", 1, "Get absolute value of a number") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return new MyComplex(parameters.get(0).abs());
        }
    });
    addFunction(new Function("LN", 1, "Logarithm base e of the argument") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double d = Math.log(parameters.get(0).real);
            return new MyComplex(d);
        }
    });
    addFunction(new Function("LOG", 1, "Logarithm base 10 of the argument") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double d = Math.log10(parameters.get(0).real);
            return new MyComplex(d);
        }
    });
    addFunction(new Function("FLOOR", 1, "Rounds DOWN to nearest Integer") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double d = Math.floor(parameters.get(0).real);
            return new MyComplex(d);
        }
    });
    addFunction(new Function("CEIL", 1, "Rounds UP to nearest Integer") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double d = Math.ceil(parameters.get(0).real);
            return new MyComplex(d);
        }
    });
    addFunction(new Function("ROU", 1, "Rounds to nearest Integer") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            int d = (int) (parameters.get(0).real + 0.5);
            return new MyComplex(d);
        }
    });
    addFunction(new Function("SQRT", 1, "Square root") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            MyComplex p = parameters.get(0);
            if (p.type == ValueType.REAL) {
                return new MyComplex(Math.sqrt(p.real));
            }
            return p.sqrt();
        }
    });
    addFunction(new Function("ARR", -1, "Create array") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            return new MyComplex(parameters);
        }
    });
    addFunction(new Function("POLY", -1, "Treat array as Polynom") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            double[] d = MyComplex.getRealArray(parameters);
            PolynomialFunction p = new PolynomialFunction(d);
            return new MyComplex(p);
        }
    });
    addFunction(new Function("DRVE", -1, "Make derivative of polynomial") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            PolynomialFunction p;
            if (parameters.get(0).isPoly()) {
                p = new PolynomialFunction(parameters.get(0).getRealArray());
            } else {
                double[] d = MyComplex.getRealArray(parameters);
                p = new PolynomialFunction(d);
            }
            return new MyComplex(p.polynomialDerivative());
        }
    });
    addFunction(new Function("ADRVE", -1, "Make antiderivative of polynomial. Constant is always zero") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            PolynomialFunction p;
            if (parameters.get(0).isPoly()) {
                p = new PolynomialFunction(parameters.get(0).getRealArray());
            } else {
                double[] d = MyComplex.getRealArray(parameters);
                p = new PolynomialFunction(d);
            }
            return new MyComplex(Misc.antiDerive(p));
        }
    });

    addFunction(new Function("PVAL", 2, "Compute value of polynom for the given argument.") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            if (parameters.get(0).isPoly()) {
                PolynomialFunction p = new PolynomialFunction(parameters.get(0).getRealArray());
                double v = p.value(parameters.get(1).real);
                return new MyComplex(v);
            }
            throw new ExpressionException("first arg must be polynomial");
        }
    });

    addFunction(new Function("INTGR", 3, "Numerical integration") {
        @Override
        public MyComplex eval(List<MyComplex> parameters) {
            if (parameters.get(0).isPoly()) {
                PolynomialFunction p = new PolynomialFunction(parameters.get(0).getRealArray());
                double start = parameters.get(1).real;
                double end = parameters.get(2).real;
                SimpsonIntegrator si = new SimpsonIntegrator();
                double d = si.integrate(1000, p, start, end);
                return new MyComplex(d);
            }
            throw new ExpressionException("first arg must be polynomial");
        }
    });

}

From source file:org.nd4j.linalg.util.BigDecimalMath.java

/**
 * The hyperbolic cosine.//ww  w  .  j av  a 2s .  c o  m
 *
 * @param x The argument.
 * @return The cosh(x) = (exp(x)+exp(-x))/2 .
 */
static public BigDecimal cosh(final BigDecimal x) {
    if (x.compareTo(BigDecimal.ZERO) < 0) {
        return cos(x.negate());
    } else if (x.compareTo(BigDecimal.ZERO) == 0) {
        return BigDecimal.ONE;
    } else {
        if (x.doubleValue() > 1.5) {
            /* cosh^2(x) = 1+ sinh^2(x).
             */
            return hypot(1, sinh(x));

        } else {
            BigDecimal xhighpr = scalePrec(x, 2);
            /* Simple Taylor expansion, sum_{0=1..infinity} x^(2i)/(2i)! */
            BigDecimal resul = BigDecimal.ONE;
            /* x^i */
            BigDecimal xpowi = BigDecimal.ONE;
            /* 2i factorial */
            BigInteger ifac = BigInteger.ONE;
            /* The absolute error in the result is the error in x^2/2 which is x times the error in x.
             */

            double xUlpDbl = 0.5 * x.ulp().doubleValue() * x.doubleValue();
            /* The error in the result is set by the error in x^2/2 itself, xUlpDbl.
             * We need at most k terms to push x^(2k)/(2k)! below this value.
             * x^(2k) < xUlpDbl; (2k)*log(x) < log(xUlpDbl);
             */

            int k = (int) (Math.log(xUlpDbl) / Math.log(x.doubleValue())) / 2;
            /* The individual terms are all smaller than 1, so an estimate of 1.0 for
             * the absolute value will give a safe relative error estimate for the indivdual terms
             */
            MathContext mcTay = new MathContext(err2prec(1., xUlpDbl / k));

            for (int i = 1;; i++) {
                /* TBD: at which precision will 2*i-1 or 2*i overflow?
                 */
                ifac = ifac.multiply(new BigInteger("" + (2 * i - 1)));
                ifac = ifac.multiply(new BigInteger("" + (2 * i)));
                xpowi = xpowi.multiply(xhighpr).multiply(xhighpr);
                BigDecimal corr = xpowi.divide(new BigDecimal(ifac), mcTay);
                resul = resul.add(corr);

                if (corr.abs().doubleValue() < 0.5 * xUlpDbl) {
                    break;
                }

            } /* The error in the result is governed by the error in x itself.
              */
            MathContext mc = new MathContext(err2prec(resul.doubleValue(), xUlpDbl));

            return resul.round(mc);

        }
    }
}

From source file:net.pms.util.Rational.java

/**
 * Returns a {@link Rational} whose value is {@code (this + value)}.
 *
 * @param value the value to be added to this {@link Rational}.
 * @return The addition result.// w w  w . j a  va2s.  c o  m
 */
@Nullable
public Rational add(@Nullable BigInteger value) {
    if (value == null) {
        return null;
    }

    if (isNaN()) {
        return NaN;
    }
    if (isInfinite() || value.signum() == 0) {
        return this;
    }

    if (BigInteger.ONE.equals(denominator)) {
        return valueOf(numerator.add(value), denominator);
    }
    return valueOf(numerator.add(value.multiply(denominator)), denominator);
}