You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@commons.apache.org by lu...@apache.org on 2010/09/05 00:59:21 UTC
svn commit: r992697 [2/4] - in /commons/proper/math/trunk/src:
main/java/org/apache/commons/math/dfp/ site/xdoc/
test/java/org/apache/commons/math/dfp/
Added: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpDec.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpDec.java?rev=992697&view=auto
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpDec.java (added)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpDec.java Sat Sep 4 22:59:21 2010
@@ -0,0 +1,359 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.math.dfp;
+
+/** Subclass of {@link Dfp} which hides the radix-10000 artifacts of the superclass.
+ * This should give outward appearances of being a decimal number with DIGITS*4-3
+ * decimal digits. This class can be subclassed to appear to be an arbitrary number
+ * of decimal digits less than DIGITS*4-3.
+ * @version $Revision$ $Date$
+ * @since 2.2
+ */
+public class DfpDec extends Dfp {
+
+ /** Makes an instance with a value of zero.
+ * @param factory factory linked to this instance
+ */
+ protected DfpDec(final DfpField factory) {
+ super(factory);
+ }
+
+ /** Create an instance from a byte value.
+ * @param factory factory linked to this instance
+ * @param x value to convert to an instance
+ */
+ protected DfpDec(final DfpField factory, byte x) {
+ super(factory, x);
+ }
+
+ /** Create an instance from an int value.
+ * @param factory factory linked to this instance
+ * @param x value to convert to an instance
+ */
+ protected DfpDec(final DfpField factory, int x) {
+ super(factory, x);
+ }
+
+ /** Create an instance from a long value.
+ * @param factory factory linked to this instance
+ * @param x value to convert to an instance
+ */
+ protected DfpDec(final DfpField factory, long x) {
+ super(factory, x);
+ }
+
+ /** Create an instance from a double value.
+ * @param factory factory linked to this instance
+ * @param x value to convert to an instance
+ */
+ protected DfpDec(final DfpField factory, double x) {
+ super(factory, x);
+ round(0);
+ }
+
+ /** Copy constructor.
+ * @param d instance to copy
+ */
+ public DfpDec(final Dfp d) {
+ super(d);
+ round(0);
+ }
+
+ /** Create an instance from a String representation.
+ * @param factory factory linked to this instance
+ * @param s string representation of the instance
+ */
+ protected DfpDec(final DfpField factory, final String s) {
+ super(factory, s);
+ round(0);
+ }
+
+ /** Creates an instance with a non-finite value.
+ * @param factory factory linked to this instance
+ * @param sign sign of the Dfp to create
+ * @param nans code of the value, must be one of {@link #INFINITE},
+ * {@link #SNAN}, {@link #QNAN}
+ */
+ protected DfpDec(final DfpField factory, final byte sign, final byte nans) {
+ super(factory, sign, nans);
+ }
+
+ /** {@inheritDoc} */
+ public Dfp newInstance() {
+ return new DfpDec(getField());
+ }
+
+ /** {@inheritDoc} */
+ public Dfp newInstance(final byte x) {
+ return new DfpDec(getField(), x);
+ }
+
+ /** {@inheritDoc} */
+ public Dfp newInstance(final int x) {
+ return new DfpDec(getField(), x);
+ }
+
+ /** {@inheritDoc} */
+ public Dfp newInstance(final long x) {
+ return new DfpDec(getField(), x);
+ }
+
+ /** {@inheritDoc} */
+ public Dfp newInstance(final double x) {
+ return new DfpDec(getField(), x);
+ }
+
+ /** {@inheritDoc} */
+ public Dfp newInstance(final Dfp d) {
+
+ // make sure we don't mix number with different precision
+ if (getField().getRadixDigits() != d.getField().getRadixDigits()) {
+ getField().setIEEEFlagsBits(DfpField.FLAG_INVALID);
+ final Dfp result = newInstance(getZero());
+ result.nans = QNAN;
+ return dotrap(DfpField.FLAG_INVALID, "newInstance", d, result);
+ }
+
+ return new DfpDec(d);
+
+ }
+
+ /** {@inheritDoc} */
+ public Dfp newInstance(final String s) {
+ return new DfpDec(getField(), s);
+ }
+
+ /** {@inheritDoc} */
+ public Dfp newInstance(final byte sign, final byte nans) {
+ return new DfpDec(getField(), sign, nans);
+ }
+
+ /** Get the number of decimal digits this class is going to represent.
+ * Default implementation returns {@link #getRadixDigits()}*4-3. Subclasses can
+ * override this to return something less.
+ * @return number of decimal digits this class is going to represent
+ */
+ protected int getDecimalDigits() {
+ return getRadixDigits() * 4 - 3;
+ }
+
+ /** {@inheritDoc} */
+ protected int round(int in) {
+
+ int msb = mant[mant.length-1];
+ if (msb == 0) {
+ // special case -- this == zero
+ return 0;
+ }
+
+ int cmaxdigits = mant.length * 4;
+ int lsbthreshold = 1000;
+ while (lsbthreshold > msb) {
+ lsbthreshold /= 10;
+ cmaxdigits --;
+ }
+
+
+ final int digits = getDecimalDigits();
+ final int lsbshift = cmaxdigits - digits;
+ final int lsd = lsbshift / 4;
+
+ lsbthreshold = 1;
+ for (int i = 0; i < lsbshift % 4; i++) {
+ lsbthreshold *= 10;
+ }
+
+ final int lsb = mant[lsd];
+
+ if (lsbthreshold <= 1 && digits == 4 * mant.length - 3) {
+ return super.round(in);
+ }
+
+ int discarded = in; // not looking at this after this point
+ final int n;
+ if (lsbthreshold == 1) {
+ // look to the next digit for rounding
+ n = (mant[lsd-1] / 1000) % 10;
+ mant[lsd-1] %= 1000;
+ discarded |= mant[lsd-1];
+ } else {
+ n = (lsb * 10 / lsbthreshold) % 10;
+ discarded |= lsb % (lsbthreshold/10);
+ }
+
+ for (int i = 0; i < lsd; i++) {
+ discarded |= mant[i]; // need to know if there are any discarded bits
+ mant[i] = 0;
+ }
+
+ mant[lsd] = lsb / lsbthreshold * lsbthreshold;
+
+ final boolean inc;
+ switch (getField().getRoundingMode()) {
+ case ROUND_DOWN:
+ inc = false;
+ break;
+
+ case ROUND_UP:
+ inc = (n != 0) || (discarded != 0); // round up if n!=0
+ break;
+
+ case ROUND_HALF_UP:
+ inc = n >= 5; // round half up
+ break;
+
+ case ROUND_HALF_DOWN:
+ inc = n > 5; // round half down
+ break;
+
+ case ROUND_HALF_EVEN:
+ inc = (n > 5) ||
+ (n == 5 && discarded != 0) ||
+ (n == 5 && discarded == 0 && ((lsb / lsbthreshold) & 1) == 1); // round half-even
+ break;
+
+ case ROUND_HALF_ODD:
+ inc = (n > 5) ||
+ (n == 5 && discarded != 0) ||
+ (n == 5 && discarded == 0 && ((lsb / lsbthreshold) & 1) == 0); // round half-odd
+ break;
+
+ case ROUND_CEIL:
+ inc = (sign == 1) && (n != 0 || discarded != 0); // round ceil
+ break;
+
+ case ROUND_FLOOR:
+ default:
+ inc = (sign == -1) && (n != 0 || discarded != 0); // round floor
+ break;
+ }
+
+ if (inc) {
+ // increment if necessary
+ int rh = lsbthreshold;
+ for (int i = lsd; i < mant.length; i++) {
+ final int r = mant[i] + rh;
+ rh = r / RADIX;
+ mant[i] = r % RADIX;
+ }
+
+ if (rh != 0) {
+ shiftRight();
+ mant[mant.length-1]=rh;
+ }
+ }
+
+ // Check for exceptional cases and raise signals if necessary
+ if (exp < MIN_EXP) {
+ // Gradual Underflow
+ getField().setIEEEFlagsBits(DfpField.FLAG_UNDERFLOW);
+ return DfpField.FLAG_UNDERFLOW;
+ }
+
+ if (exp > MAX_EXP) {
+ // Overflow
+ getField().setIEEEFlagsBits(DfpField.FLAG_OVERFLOW);
+ return DfpField.FLAG_OVERFLOW;
+ }
+
+ if (n != 0 || discarded != 0) {
+ // Inexact
+ getField().setIEEEFlagsBits(DfpField.FLAG_INEXACT);
+ return DfpField.FLAG_INEXACT;
+ }
+ return 0;
+ }
+
+ /** {@inheritDoc} */
+ public Dfp nextAfter(Dfp x) {
+
+ final String trapName = "nextAfter";
+
+ // make sure we don't mix number with different precision
+ if (getField().getRadixDigits() != x.getField().getRadixDigits()) {
+ getField().setIEEEFlagsBits(DfpField.FLAG_INVALID);
+ final Dfp result = newInstance(getZero());
+ result.nans = QNAN;
+ return dotrap(DfpField.FLAG_INVALID, trapName, x, result);
+ }
+
+ boolean up = false;
+ Dfp result;
+ Dfp inc;
+
+ // if this is greater than x
+ if (this.lessThan(x)) {
+ up = true;
+ }
+
+ if (equals(x)) {
+ return newInstance(x);
+ }
+
+ if (lessThan(getZero())) {
+ up = !up;
+ }
+
+ if (up) {
+ inc = power10(log10() - getDecimalDigits() + 1);
+ inc = copysign(inc, this);
+
+ if (this.equals(getZero())) {
+ inc = power10K(MIN_EXP-mant.length-1);
+ }
+
+ if (inc.equals(getZero())) {
+ result = copysign(newInstance(getZero()), this);
+ } else {
+ result = add(inc);
+ }
+ } else {
+ inc = power10(log10());
+ inc = copysign(inc, this);
+
+ if (this.equals(inc)) {
+ inc = inc.divide(power10(getDecimalDigits()));
+ } else {
+ inc = inc.divide(power10(getDecimalDigits() - 1));
+ }
+
+ if (this.equals(getZero())) {
+ inc = power10K(MIN_EXP-mant.length-1);
+ }
+
+ if (inc.equals(getZero())) {
+ result = copysign(newInstance(getZero()), this);
+ } else {
+ result = subtract(inc);
+ }
+ }
+
+ if (result.classify() == INFINITE && this.classify() != INFINITE) {
+ getField().setIEEEFlagsBits(DfpField.FLAG_INEXACT);
+ result = dotrap(DfpField.FLAG_INEXACT, trapName, x, result);
+ }
+
+ if (result.equals(getZero()) && this.equals(getZero()) == false) {
+ getField().setIEEEFlagsBits(DfpField.FLAG_INEXACT);
+ result = dotrap(DfpField.FLAG_INEXACT, trapName, x, result);
+ }
+
+ return result;
+ }
+
+}
Propchange: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpDec.java
------------------------------------------------------------------------------
svn:eol-style = native
Propchange: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpDec.java
------------------------------------------------------------------------------
svn:keywords = Author Date Id Revision
Added: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpField.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpField.java?rev=992697&view=auto
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpField.java (added)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpField.java Sat Sep 4 22:59:21 2010
@@ -0,0 +1,742 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.math.dfp;
+
+import org.apache.commons.math.Field;
+
+/** Field for Decimal floating point instances.
+ * @version $Revision$ $Date$
+ * @since 2.2
+ */
+public class DfpField implements Field<Dfp> {
+
+ /** Enumerate for rounding modes. */
+ public enum RoundingMode {
+
+ /** Rounds toward zero (truncation). */
+ ROUND_DOWN,
+
+ /** Rounds away from zero if discarded digit is non-zero. */
+ ROUND_UP,
+
+ /** Rounds towards nearest unless both are equidistant in which case it rounds away from zero. */
+ ROUND_HALF_UP,
+
+ /** Rounds towards nearest unless both are equidistant in which case it rounds toward zero. */
+ ROUND_HALF_DOWN,
+
+ /** Rounds towards nearest unless both are equidistant in which case it rounds toward the even neighbor.
+ * This is the default as specified by IEEE 854-1987
+ */
+ ROUND_HALF_EVEN,
+
+ /** Rounds towards nearest unless both are equidistant in which case it rounds toward the odd neighbor. */
+ ROUND_HALF_ODD,
+
+ /** Rounds towards positive infinity. */
+ ROUND_CEIL,
+
+ /** Rounds towards negative infinity. */
+ ROUND_FLOOR;
+
+ }
+
+ /** IEEE 854-1987 flag for invalid operation. */
+ public static final int FLAG_INVALID = 1;
+
+ /** IEEE 854-1987 flag for division by zero. */
+ public static final int FLAG_DIV_ZERO = 2;
+
+ /** IEEE 854-1987 flag for overflow. */
+ public static final int FLAG_OVERFLOW = 4;
+
+ /** IEEE 854-1987 flag for underflow. */
+ public static final int FLAG_UNDERFLOW = 8;
+
+ /** IEEE 854-1987 flag for inexact result. */
+ public static final int FLAG_INEXACT = 16;
+
+ /** High precision string representation of √2. */
+ private static String sqr2String;
+
+ /** High precision string representation of √2 / 2. */
+ private static String sqr2ReciprocalString;
+
+ /** High precision string representation of √3. */
+ private static String sqr3String;
+
+ /** High precision string representation of √3 / 3. */
+ private static String sqr3ReciprocalString;
+
+ /** High precision string representation of π. */
+ private static String piString;
+
+ /** High precision string representation of e. */
+ private static String eString;
+
+ /** High precision string representation of ln(2). */
+ private static String ln2String;
+
+ /** High precision string representation of ln(5). */
+ private static String ln5String;
+
+ /** High precision string representation of ln(10). */
+ private static String ln10String;
+
+ /** The number of radix digits.
+ * Note these depend on the radix which is 10000 digits,
+ * so each one is equivalent to 4 decimal digits.
+ */
+ private final int radixDigits;
+
+ /** A {@link Dfp} with value 0. */
+ private final Dfp zero;
+
+ /** A {@link Dfp} with value 1. */
+ private final Dfp one;
+
+ /** A {@link Dfp} with value 2. */
+ private final Dfp two;
+
+ /** A {@link Dfp} with value √2. */
+ private final Dfp sqr2;
+
+ /** A two elements {@link Dfp} array with value √2 split in two pieces. */
+ private final Dfp[] sqr2Split;
+
+ /** A {@link Dfp} with value √2 / 2. */
+ private final Dfp sqr2Reciprocal;
+
+ /** A {@link Dfp} with value √3. */
+ private final Dfp sqr3;
+
+ /** A {@link Dfp} with value √3 / 3. */
+ private final Dfp sqr3Reciprocal;
+
+ /** A {@link Dfp} with value π. */
+ private final Dfp pi;
+
+ /** A two elements {@link Dfp} array with value π split in two pieces. */
+ private final Dfp[] piSplit;
+
+ /** A {@link Dfp} with value e. */
+ private final Dfp e;
+
+ /** A two elements {@link Dfp} array with value e split in two pieces. */
+ private final Dfp[] eSplit;
+
+ /** A {@link Dfp} with value ln(2). */
+ private final Dfp ln2;
+
+ /** A two elements {@link Dfp} array with value ln(2) split in two pieces. */
+ private final Dfp[] ln2Split;
+
+ /** A {@link Dfp} with value ln(5). */
+ private final Dfp ln5;
+
+ /** A two elements {@link Dfp} array with value ln(5) split in two pieces. */
+ private final Dfp[] ln5Split;
+
+ /** A {@link Dfp} with value ln(10). */
+ private final Dfp ln10;
+
+ /** Current rounding mode. */
+ private RoundingMode rMode;
+
+ /** IEEE 854-1987 signals. */
+ private int ieeeFlags;
+
+ /** Create a factory for the specified number of radix digits.
+ * <p>
+ * Note that since the {@link Dfp} class uses 10000 as its radix, each radix
+ * digit is equivalent to 4 decimal digits. This implies that asking for
+ * 13, 14, 15 or 16 decimal digits will really lead to a 4 radix 10000 digits in
+ * all cases.
+ * </p>
+ * @param decimalDigits minimal number of decimal digits.
+ */
+ public DfpField(final int decimalDigits) {
+ this(decimalDigits, true);
+ }
+
+ /** Create a factory for the specified number of radix digits.
+ * <p>
+ * Note that since the {@link Dfp} class uses 10000 as its radix, each radix
+ * digit is equivalent to 4 decimal digits. This implies that asking for
+ * 13, 14, 15 or 16 decimal digits will really lead to a 4 radix 10000 digits in
+ * all cases.
+ * </p>
+ * @param decimalDigits minimal number of decimal digits
+ * @param computeConstants if true, the transcendental constants for the given precision
+ * must be computed (setting this flag to false is RESERVED for the internal recursive call)
+ */
+ public DfpField(final int decimalDigits, final boolean computeConstants) {
+
+ this.radixDigits = (decimalDigits + 3) / 4;
+ this.rMode = RoundingMode.ROUND_HALF_EVEN;
+ this.ieeeFlags = 0;
+ this.zero = new Dfp(this, 0);
+ this.one = new Dfp(this, 1);
+ this.two = new Dfp(this, 2);
+
+ if (computeConstants) {
+ // set up transcendental constants
+ synchronized (DfpField.class) {
+
+ // as a heuristic to circumvent Table-Maker's Dilemma, we set the string
+ // representation of the constants to be at least 3 times larger than the
+ // number of decimal digits, also as an attempt to really compute these
+ // constants only once, we set a minimum number of digits
+ computeStringConstants((decimalDigits < 67) ? 200 : (3 * decimalDigits));
+
+ // set up the constants at current field accuracy
+ sqr2 = new Dfp(this, sqr2String);
+ sqr2Split = split(sqr2String);
+ sqr2Reciprocal = new Dfp(this, sqr2ReciprocalString);
+ sqr3 = new Dfp(this, sqr3String);
+ sqr3Reciprocal = new Dfp(this, sqr3ReciprocalString);
+ pi = new Dfp(this, piString);
+ piSplit = split(piString);
+ e = new Dfp(this, eString);
+ eSplit = split(eString);
+ ln2 = new Dfp(this, ln2String);
+ ln2Split = split(ln2String);
+ ln5 = new Dfp(this, ln5String);
+ ln5Split = split(ln5String);
+ ln10 = new Dfp(this, ln10String);
+
+ }
+ } else {
+ // dummy settings for unused constants
+ sqr2 = null;
+ sqr2Split = null;
+ sqr2Reciprocal = null;
+ sqr3 = null;
+ sqr3Reciprocal = null;
+ pi = null;
+ piSplit = null;
+ e = null;
+ eSplit = null;
+ ln2 = null;
+ ln2Split = null;
+ ln5 = null;
+ ln5Split = null;
+ ln10 = null;
+ }
+
+ }
+
+ /** Get the number of radix digits of the {@link Dfp} instances built by this factory.
+ * @return number of radix digits
+ */
+ public int getRadixDigits() {
+ return radixDigits;
+ }
+
+ /** Set the rounding mode.
+ * If not set, the default value is {@link RoundingMode#ROUND_HALF_EVEN}.
+ * @param mode desired rounding mode
+ * Note that the rounding mode is common to all {@link Dfp} instances
+ * belonging to the current {@link DfpField} in the system and will
+ * affect all future calculations.
+ */
+ public void setRoundingMode(final RoundingMode mode) {
+ rMode = mode;
+ }
+
+ /** Get the current rounding mode.
+ * @return current rounding mode
+ */
+ public RoundingMode getRoundingMode() {
+ return rMode;
+ }
+
+ /** Get the IEEE 854 status flags.
+ * @return IEEE 854 status flags
+ * @see #clearIEEEFlags()
+ * @see #setIEEEFlags(int)
+ * @see #setIEEEFlagsBits(int)
+ * @see #FLAG_INVALID
+ * @see #FLAG_DIV_ZERO
+ * @see #FLAG_OVERFLOW
+ * @see #FLAG_UNDERFLOW
+ * @see #FLAG_INEXACT
+ */
+ public int getIEEEFlags() {
+ return ieeeFlags;
+ }
+
+ /** Clears the IEEE 854 status flags.
+ * @see #getIEEEFlags()
+ * @see #setIEEEFlags(int)
+ * @see #setIEEEFlagsBits(int)
+ * @see #FLAG_INVALID
+ * @see #FLAG_DIV_ZERO
+ * @see #FLAG_OVERFLOW
+ * @see #FLAG_UNDERFLOW
+ * @see #FLAG_INEXACT
+ */
+ public void clearIEEEFlags() {
+ ieeeFlags = 0;
+ }
+
+ /** Sets the IEEE 854 status flags.
+ * @param flags desired value for the flags
+ * @see #getIEEEFlags()
+ * @see #clearIEEEFlags()
+ * @see #setIEEEFlagsBits(int)
+ * @see #FLAG_INVALID
+ * @see #FLAG_DIV_ZERO
+ * @see #FLAG_OVERFLOW
+ * @see #FLAG_UNDERFLOW
+ * @see #FLAG_INEXACT
+ */
+ public void setIEEEFlags(final int flags) {
+ ieeeFlags = flags & (FLAG_INVALID | FLAG_DIV_ZERO | FLAG_OVERFLOW | FLAG_UNDERFLOW | FLAG_INEXACT);
+ }
+
+ /** Sets some bits in the IEEE 854 status flags, without changing the already set bits.
+ * <p>
+ * Calling this method is equivalent to call {@code setIEEEFlags(getIEEEFlags() | bits)}
+ * </p>
+ * @param bits bits to set
+ * @see #getIEEEFlags()
+ * @see #clearIEEEFlags()
+ * @see #setIEEEFlags(int)
+ * @see #FLAG_INVALID
+ * @see #FLAG_DIV_ZERO
+ * @see #FLAG_OVERFLOW
+ * @see #FLAG_UNDERFLOW
+ * @see #FLAG_INEXACT
+ */
+ public void setIEEEFlagsBits(final int bits) {
+ ieeeFlags |= bits & (FLAG_INVALID | FLAG_DIV_ZERO | FLAG_OVERFLOW | FLAG_UNDERFLOW | FLAG_INEXACT);
+ }
+
+ /** Makes a {@link Dfp} with a value of 0.
+ * @return a new {@link Dfp} with a value of 0
+ */
+ public Dfp newDfp() {
+ return new Dfp(this);
+ }
+
+ /** Create an instance from a byte value.
+ * @param x value to convert to an instance
+ * @return a new {@link Dfp} with the same value as x
+ */
+ public Dfp newDfp(final byte x) {
+ return new Dfp(this, x);
+ }
+
+ /** Create an instance from an int value.
+ * @param x value to convert to an instance
+ * @return a new {@link Dfp} with the same value as x
+ */
+ public Dfp newDfp(final int x) {
+ return new Dfp(this, x);
+ }
+
+ /** Create an instance from a long value.
+ * @param x value to convert to an instance
+ * @return a new {@link Dfp} with the same value as x
+ */
+ public Dfp newDfp(final long x) {
+ return new Dfp(this, x);
+ }
+
+ /** Create an instance from a double value.
+ * @param x value to convert to an instance
+ * @return a new {@link Dfp} with the same value as x
+ */
+ public Dfp newDfp(final double x) {
+ return new Dfp(this, x);
+ }
+
+ /** Copy constructor.
+ * @param d instance to copy
+ * @return a new {@link Dfp} with the same value as d
+ */
+ public Dfp newDfp(Dfp d) {
+ return new Dfp(d);
+ }
+
+ /** Create a {@link Dfp} given a String representation.
+ * @param s string representation of the instance
+ * @return a new {@link Dfp} parsed from specified string
+ */
+ public Dfp newDfp(final String s) {
+ return new Dfp(this, s);
+ }
+
+ /** Creates a {@link Dfp} with a non-finite value.
+ * @param sign sign of the Dfp to create
+ * @param nans code of the value, must be one of {@link Dfp#INFINITE},
+ * {@link Dfp#SNAN}, {@link Dfp#QNAN}
+ * @return a new {@link Dfp} with a non-finite value
+ */
+ public Dfp newDfp(final byte sign, final byte nans) {
+ return new Dfp(this, sign, nans);
+ }
+
+ /** Get the constant 0.
+ * @return a {@link Dfp} with value 0
+ */
+ public Dfp getZero() {
+ return zero;
+ }
+
+ /** Get the constant 1.
+ * @return a {@link Dfp} with value 1
+ */
+ public Dfp getOne() {
+ return one;
+ }
+
+ /** Get the constant 2.
+ * @return a {@link Dfp} with value 2
+ */
+ public Dfp getTwo() {
+ return two;
+ }
+
+ /** Get the constant √2.
+ * @return a {@link Dfp} with value √2
+ */
+ public Dfp getSqr2() {
+ return sqr2;
+ }
+
+ /** Get the constant √2 split in two pieces.
+ * @return a {@link Dfp} with value √2 split in two pieces
+ */
+ public Dfp[] getSqr2Split() {
+ return sqr2Split.clone();
+ }
+
+ /** Get the constant √2 / 2.
+ * @return a {@link Dfp} with value √2 / 2
+ */
+ public Dfp getSqr2Reciprocal() {
+ return sqr2Reciprocal;
+ }
+
+ /** Get the constant √3.
+ * @return a {@link Dfp} with value √3
+ */
+ public Dfp getSqr3() {
+ return sqr3;
+ }
+
+ /** Get the constant √3 / 3.
+ * @return a {@link Dfp} with value √3 / 3
+ */
+ public Dfp getSqr3Reciprocal() {
+ return sqr3Reciprocal;
+ }
+
+ /** Get the constant π.
+ * @return a {@link Dfp} with value π
+ */
+ public Dfp getPi() {
+ return pi;
+ }
+
+ /** Get the constant π split in two pieces.
+ * @return a {@link Dfp} with value π split in two pieces
+ */
+ public Dfp[] getPiSplit() {
+ return piSplit.clone();
+ }
+
+ /** Get the constant e.
+ * @return a {@link Dfp} with value e
+ */
+ public Dfp getE() {
+ return e;
+ }
+
+ /** Get the constant e split in two pieces.
+ * @return a {@link Dfp} with value e split in two pieces
+ */
+ public Dfp[] getESplit() {
+ return eSplit.clone();
+ }
+
+ /** Get the constant ln(2).
+ * @return a {@link Dfp} with value ln(2)
+ */
+ public Dfp getLn2() {
+ return ln2;
+ }
+
+ /** Get the constant ln(2) split in two pieces.
+ * @return a {@link Dfp} with value ln(2) split in two pieces
+ */
+ public Dfp[] getLn2Split() {
+ return ln2Split.clone();
+ }
+
+ /** Get the constant ln(5).
+ * @return a {@link Dfp} with value ln(5)
+ */
+ public Dfp getLn5() {
+ return ln5;
+ }
+
+ /** Get the constant ln(5) split in two pieces.
+ * @return a {@link Dfp} with value ln(5) split in two pieces
+ */
+ public Dfp[] getLn5Split() {
+ return ln5Split.clone();
+ }
+
+ /** Get the constant ln(10).
+ * @return a {@link Dfp} with value ln(10)
+ */
+ public Dfp getLn10() {
+ return ln10;
+ }
+
+ /** Breaks a string representation up into two {@link Dfp}'s.
+ * The split is such that the sum of them is equivalent to the input string,
+ * but has higher precision than using a single Dfp.
+ * @param a string representation of the number to split
+ * @return an array of two {@link Dfp Dfp} instances which sum equals a
+ */
+ private Dfp[] split(final String a) {
+ Dfp result[] = new Dfp[2];
+ boolean leading = true;
+ int sp = 0;
+ int sig = 0;
+
+ char[] buf = new char[a.length()];
+
+ for (int i = 0; i < buf.length; i++) {
+ buf[i] = a.charAt(i);
+
+ if (buf[i] >= '1' && buf[i] <= '9') {
+ leading = false;
+ }
+
+ if (buf[i] == '.') {
+ sig += (400 - sig) % 4;
+ leading = false;
+ }
+
+ if (sig == (radixDigits / 2) * 4) {
+ sp = i;
+ break;
+ }
+
+ if (buf[i] >= '0' && buf[i] <= '9' && !leading) {
+ sig ++;
+ }
+ }
+
+ result[0] = new Dfp(this, new String(buf, 0, sp));
+
+ for (int i = 0; i < buf.length; i++) {
+ buf[i] = a.charAt(i);
+ if (buf[i] >= '0' && buf[i] <= '9' && i < sp) {
+ buf[i] = '0';
+ }
+ }
+
+ result[1] = new Dfp(this, new String(buf));
+
+ return result;
+
+ }
+
+ /** Recompute the high precision string constants.
+ * @param highPrecisionDecimalDigits precision at which the string constants mus be computed
+ */
+ private static void computeStringConstants(final int highPrecisionDecimalDigits) {
+ if (sqr2String == null || sqr2String.length() < highPrecisionDecimalDigits - 3) {
+
+ // recompute the string representation of the transcendental constants
+ final DfpField highPrecisionField = new DfpField(highPrecisionDecimalDigits, false);
+ final Dfp highPrecisionOne = new Dfp(highPrecisionField, 1);
+ final Dfp highPrecisionTwo = new Dfp(highPrecisionField, 2);
+ final Dfp highPrecisionThree = new Dfp(highPrecisionField, 3);
+
+ final Dfp highPrecisionSqr2 = highPrecisionTwo.sqrt();
+ sqr2String = highPrecisionSqr2.toString();
+ sqr2ReciprocalString = highPrecisionOne.divide(highPrecisionSqr2).toString();
+
+ final Dfp highPrecisionSqr3 = highPrecisionThree.sqrt();
+ sqr3String = highPrecisionSqr3.toString();
+ sqr3ReciprocalString = highPrecisionOne.divide(highPrecisionSqr3).toString();
+
+ piString = computePi(highPrecisionOne, highPrecisionTwo, highPrecisionThree).toString();
+ eString = computeExp(highPrecisionOne, highPrecisionOne).toString();
+ ln2String = computeLn(highPrecisionTwo, highPrecisionOne, highPrecisionTwo).toString();
+ ln5String = computeLn(new Dfp(highPrecisionField, 5), highPrecisionOne, highPrecisionTwo).toString();
+ ln10String = computeLn(new Dfp(highPrecisionField, 10), highPrecisionOne, highPrecisionTwo).toString();
+
+ }
+ }
+
+ /** Compute π by atan(1/√(3)) = π/6.
+ * @param one constant with value 1 at desired precision
+ * @param two constant with value 2 at desired precision
+ * @param three constant with value 3 at desired precision
+ * @return π
+ */
+ private static Dfp computePi(final Dfp one, final Dfp two, final Dfp three) {
+
+ Dfp x = three;
+ x = x.sqrt();
+ x = one.divide(x);
+
+ Dfp denom = one;
+
+ Dfp py = new Dfp(x);
+ Dfp y = new Dfp(x);
+
+ for (int i = 1; i < 10000; i++) {
+ x = x.divide(three);
+ denom = denom.add(two);
+ if ((i&1) != 0) {
+ y = y.subtract(x.divide(denom));
+ } else {
+ y = y.add(x.divide(denom));
+ }
+ if (y.equals(py)) {
+ break;
+ }
+ py = new Dfp(y);
+ }
+
+ return y.multiply(new Dfp(one.getField(), 6));
+
+ }
+
+ /** Compute exp(a).
+ * @param a number for which we want the exponential
+ * @param one constant with value 1 at desired precision
+ * @return exp(a)
+ */
+ public static Dfp computeExp(final Dfp a, final Dfp one) {
+
+ Dfp y = new Dfp(one);
+ Dfp py = new Dfp(one);
+ Dfp f = new Dfp(one);
+ Dfp fi = new Dfp(one);
+ Dfp x = new Dfp(one);
+
+ for (int i = 0; i < 10000; i++) {
+ x = x.multiply(a);
+ y = y.add(x.divide(f));
+ fi = fi.add(one);
+ f = f.multiply(fi);
+ if (y.equals(py)) {
+ break;
+ }
+ py = new Dfp(y);
+ }
+
+ return y;
+
+ }
+
+
+ /** Compute ln(a).
+ *
+ * Let f(x) = ln(x),
+ *
+ * We know that f'(x) = 1/x, thus from Taylor's theorem we have:
+ *
+ * ----- n+1 n
+ * f(x) = \ (-1) (x - 1)
+ * / ---------------- for 1 <= n <= infinity
+ * ----- n
+ *
+ * or
+ * 2 3 4
+ * (x-1) (x-1) (x-1)
+ * ln(x) = (x-1) - ----- + ------ - ------ + ...
+ * 2 3 4
+ *
+ * alternatively,
+ *
+ * 2 3 4
+ * x x x
+ * ln(x+1) = x - - + - - - + ...
+ * 2 3 4
+ *
+ * This series can be used to compute ln(x), but it converges too slowly.
+ *
+ * If we substitute -x for x above, we get
+ *
+ * 2 3 4
+ * x x x
+ * ln(1-x) = -x - - - - - - + ...
+ * 2 3 4
+ *
+ * Note that all terms are now negative. Because the even powered ones
+ * absorbed the sign. Now, subtract the series above from the previous
+ * one to get ln(x+1) - ln(1-x). Note the even terms cancel out leaving
+ * only the odd ones
+ *
+ * 3 5 7
+ * 2x 2x 2x
+ * ln(x+1) - ln(x-1) = 2x + --- + --- + ---- + ...
+ * 3 5 7
+ *
+ * By the property of logarithms that ln(a) - ln(b) = ln (a/b) we have:
+ *
+ * 3 5 7
+ * x+1 / x x x \
+ * ln ----- = 2 * | x + ---- + ---- + ---- + ... |
+ * x-1 \ 3 5 7 /
+ *
+ * But now we want to find ln(a), so we need to find the value of x
+ * such that a = (x+1)/(x-1). This is easily solved to find that
+ * x = (a-1)/(a+1).
+ * @param a number for which we want the exponential
+ * @param one constant with value 1 at desired precision
+ * @param two constant with value 2 at desired precision
+ * @return ln(a)
+ */
+
+ public static Dfp computeLn(final Dfp a, final Dfp one, final Dfp two) {
+
+ int den = 1;
+ Dfp x = a.add(new Dfp(a.getField(), -1)).divide(a.add(one));
+
+ Dfp y = new Dfp(x);
+ Dfp num = new Dfp(x);
+ Dfp py = new Dfp(y);
+ for (int i = 0; i < 10000; i++) {
+ num = num.multiply(x);
+ num = num.multiply(x);
+ den = den + 2;
+ Dfp t = num.divide(den);
+ y = y.add(t);
+ if (y.equals(py)) {
+ break;
+ }
+ py = new Dfp(y);
+ }
+
+ return y.multiply(two);
+
+ }
+
+}
Propchange: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpField.java
------------------------------------------------------------------------------
svn:eol-style = native
Propchange: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpField.java
------------------------------------------------------------------------------
svn:keywords = Author Date Id Revision
Added: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpMath.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpMath.java?rev=992697&view=auto
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpMath.java (added)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpMath.java Sat Sep 4 22:59:21 2010
@@ -0,0 +1,969 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.math.dfp;
+
+/** Mathematical routines for use with {@link Dfp}.
+ * The constants are defined in {@link DfpField}
+ * @version $Revision$ $Date$
+ * @since 2.2
+ */
+public class DfpMath {
+
+ /** Name for traps triggered by pow. */
+ private static final String POW_TRAP = "pow";
+
+ /**
+ * Private Constructor.
+ */
+ private DfpMath() {
+ }
+
+ /** Breaks a string representation up into two dfp's.
+ * <p>The two dfp are such that the sum of them is equivalent
+ * to the input string, but has higher precision than using a
+ * single dfp. This is useful for improving accuracy of
+ * exponentiation and critical multiplies.
+ * @param field field to which the Dfp must belong
+ * @param a string representation to split
+ * @return an array of two {@link Dfp} which sum is a
+ */
+ protected static Dfp[] split(final DfpField field, final String a) {
+ Dfp result[] = new Dfp[2];
+ char[] buf;
+ boolean leading = true;
+ int sp = 0;
+ int sig = 0;
+
+ buf = new char[a.length()];
+
+ for (int i = 0; i < buf.length; i++) {
+ buf[i] = a.charAt(i);
+
+ if (buf[i] >= '1' && buf[i] <= '9') {
+ leading = false;
+ }
+
+ if (buf[i] == '.') {
+ sig += (400 - sig) % 4;
+ leading = false;
+ }
+
+ if (sig == (field.getRadixDigits() / 2) * 4) {
+ sp = i;
+ break;
+ }
+
+ if (buf[i] >= '0' && buf[i] <= '9' && !leading) {
+ sig ++;
+ }
+ }
+
+ result[0] = field.newDfp(new String(buf, 0, sp));
+
+ for (int i = 0; i < buf.length; i++) {
+ buf[i] = a.charAt(i);
+ if (buf[i] >= '0' && buf[i] <= '9' && i < sp) {
+ buf[i] = '0';
+ }
+ }
+
+ result[1] = field.newDfp(new String(buf));
+
+ return result;
+ }
+
+ /** Splits a {@link Dfp} into 2 {@link Dfp}'s such that their sum is equal to the input {@link Dfp}.
+ * @param a number to split
+ * @return two elements array containing the split number
+ */
+ protected static Dfp[] split(final Dfp a) {
+ final Dfp[] result = new Dfp[2];
+ final Dfp shift = a.multiply(a.power10K(a.getRadixDigits() / 2));
+ result[0] = a.add(shift).subtract(shift);
+ result[1] = a.subtract(result[0]);
+ return result;
+ }
+
+ /** Multiply two numbers that are split in to two pieces that are
+ * meant to be added together.
+ * Use binomial multiplication so ab = a0 b0 + a0 b1 + a1 b0 + a1 b1
+ * Store the first term in result0, the rest in result1
+ * @param a first factor of the multiplication, in split form
+ * @param b second factor of the multiplication, in split form
+ * @return a × b, in split form
+ */
+ protected static Dfp[] splitMult(final Dfp[] a, final Dfp[] b) {
+ final Dfp[] result = new Dfp[2];
+
+ result[1] = a[0].getZero();
+ result[0] = a[0].multiply(b[0]);
+
+ /* If result[0] is infinite or zero, don't compute result[1].
+ * Attempting to do so may produce NaNs.
+ */
+
+ if (result[0].classify() == Dfp.INFINITE || result[0].equals(result[1])) {
+ return result;
+ }
+
+ result[1] = a[0].multiply(b[1]).add(a[1].multiply(b[0])).add(a[1].multiply(b[1]));
+
+ return result;
+ }
+
+ /** Divide two numbers that are split in to two pieces that are meant to be added together.
+ * Inverse of split multiply above:
+ * (a+b) / (c+d) = (a/c) + ( (bc-ad)/(c**2+cd) )
+ * @param a dividend, in split form
+ * @param b divisor, in split form
+ * @return a / b, in split form
+ */
+ protected static Dfp[] splitDiv(final Dfp[] a, final Dfp[] b) {
+ final Dfp[] result;
+
+ result = new Dfp[2];
+
+ result[0] = a[0].divide(b[0]);
+ result[1] = a[1].multiply(b[0]).subtract(a[0].multiply(b[1]));
+ result[1] = result[1].divide(b[0].multiply(b[0]).add(b[0].multiply(b[1])));
+
+ return result;
+ }
+
+ /** Raise a split base to the a power.
+ * @param base number to raise
+ * @param a power
+ * @return base<sup>a</sup>
+ */
+ protected static Dfp splitPow(final Dfp[] base, int a) {
+ boolean invert = false;
+
+ Dfp[] r = new Dfp[2];
+
+ Dfp[] result = new Dfp[2];
+ result[0] = base[0].getOne();
+ result[1] = base[0].getZero();
+
+ if (a == 0) {
+ // Special case a = 0
+ return result[0].add(result[1]);
+ }
+
+ if (a < 0) {
+ // If a is less than zero
+ invert = true;
+ a = -a;
+ }
+
+ // Exponentiate by successive squaring
+ do {
+ r[0] = new Dfp(base[0]);
+ r[1] = new Dfp(base[1]);
+ int trial = 1;
+
+ int prevtrial;
+ while (true) {
+ prevtrial = trial;
+ trial = trial * 2;
+ if (trial > a) {
+ break;
+ }
+ r = splitMult(r, r);
+ }
+
+ trial = prevtrial;
+
+ a -= trial;
+ result = splitMult(result, r);
+
+ } while (a >= 1);
+
+ result[0] = result[0].add(result[1]);
+
+ if (invert) {
+ result[0] = base[0].getOne().divide(result[0]);
+ }
+
+ return result[0];
+
+ }
+
+ /** Raises base to the power a by successive squaring.
+ * @param base number to raise
+ * @param a power
+ * @return base<sup>a</sup>
+ */
+ public static Dfp pow(Dfp base, int a)
+ {
+ boolean invert = false;
+
+ Dfp result = base.getOne();
+
+ if (a == 0) {
+ // Special case
+ return result;
+ }
+
+ if (a < 0) {
+ invert = true;
+ a = -a;
+ }
+
+ // Exponentiate by successive squaring
+ do {
+ Dfp r = new Dfp(base);
+ Dfp prevr;
+ int trial = 1;
+ int prevtrial;
+
+ do {
+ prevr = new Dfp(r);
+ prevtrial = trial;
+ r = r.multiply(r);
+ trial = trial * 2;
+ } while (a>trial);
+
+ r = prevr;
+ trial = prevtrial;
+
+ a = a - trial;
+ result = result.multiply(r);
+
+ } while (a >= 1);
+
+ if (invert) {
+ result = base.getOne().divide(result);
+ }
+
+ return base.newInstance(result);
+
+ }
+
+ /** Computes e to the given power.
+ * a is broken into two parts, such that a = n+m where n is an integer.
+ * We use pow() to compute e<sup>n</sup> and a Taylor series to compute
+ * e<sup>m</sup>. We return e*<sup>n</sup> × e<sup>m</sup>
+ * @param a power at which e should be raised
+ * @return e<sup>a</sup>
+ */
+ public static Dfp exp(final Dfp a) {
+
+ final Dfp inta = a.rint();
+ final Dfp fraca = a.subtract(inta);
+
+ final int ia = inta.intValue();
+ if (ia > 2147483646) {
+ // return +Infinity
+ return a.newInstance((byte)1, (byte) Dfp.INFINITE);
+ }
+
+ if (ia < -2147483646) {
+ // return 0;
+ return a.newInstance();
+ }
+
+ final Dfp einta = splitPow(a.getField().getESplit(), ia);
+ final Dfp efraca = expInternal(fraca);
+
+ return einta.multiply(efraca);
+ }
+
+ /** Computes e to the given power.
+ * Where -1 < a < 1. Use the classic Taylor series. 1 + x**2/2! + x**3/3! + x**4/4! ...
+ * @param a power at which e should be raised
+ * @return e<sup>a</sup>
+ */
+ protected static Dfp expInternal(final Dfp a) {
+ Dfp y = a.getOne();
+ Dfp x = a.getOne();
+ Dfp fact = a.getOne();
+ Dfp py = new Dfp(y);
+
+ for (int i = 1; i < 90; i++) {
+ x = x.multiply(a);
+ fact = fact.divide(i);
+ y = y.add(x.multiply(fact));
+ if (y.equals(py)) {
+ break;
+ }
+ py = new Dfp(y);
+ }
+
+ return y;
+ }
+
+ /** Returns the natural logarithm of a.
+ * a is first split into three parts such that a = (10000^h)(2^j)k.
+ * ln(a) is computed by ln(a) = ln(5)*h + ln(2)*(h+j) + ln(k)
+ * k is in the range 2/3 < k <4/3 and is passed on to a series expansion.
+ * @param a number from which logarithm is requested
+ * @return log(a)
+ */
+ public static Dfp log(Dfp a) {
+ int lr;
+ Dfp x;
+ int ix;
+ int p2 = 0;
+
+ // Check the arguments somewhat here
+ if (a.equals(a.getZero()) || a.lessThan(a.getZero()) || (a.equals(a) == false)) {
+ // negative, zero or NaN
+ a.getField().setIEEEFlagsBits(DfpField.FLAG_INVALID);
+ return a.dotrap(DfpField.FLAG_INVALID, "ln", a, a.newInstance((byte)1, (byte) Dfp.QNAN));
+ }
+
+ if (a.classify() == Dfp.INFINITE) {
+ return a;
+ }
+
+ x = new Dfp(a);
+ lr = x.log10K();
+
+ x = x.divide(pow(a.newInstance(10000), lr)); /* This puts x in the range 0-10000 */
+ ix = x.floor().intValue();
+
+ while (ix > 2) {
+ ix >>= 1;
+ p2++;
+ }
+
+
+ Dfp[] spx = split(x);
+ Dfp[] spy = new Dfp[2];
+ spy[0] = pow(a.getTwo(), p2); // use spy[0] temporarily as a divisor
+ spx[0] = spx[0].divide(spy[0]);
+ spx[1] = spx[1].divide(spy[0]);
+
+ spy[0] = a.newInstance("1.33333"); // Use spy[0] for comparison
+ while (spx[0].add(spx[1]).greaterThan(spy[0])) {
+ spx[0] = spx[0].divide(2);
+ spx[1] = spx[1].divide(2);
+ p2++;
+ }
+
+ // X is now in the range of 2/3 < x < 4/3
+ Dfp[] spz = logInternal(spx);
+
+ spx[0] = a.newInstance(new StringBuffer().append(p2+4*lr).toString());
+ spx[1] = a.getZero();
+ spy = splitMult(a.getField().getLn2Split(), spx);
+
+ spz[0] = spz[0].add(spy[0]);
+ spz[1] = spz[1].add(spy[1]);
+
+ spx[0] = a.newInstance(new StringBuffer().append(4*lr).toString());
+ spx[1] = a.getZero();
+ spy = splitMult(a.getField().getLn5Split(), spx);
+
+ spz[0] = spz[0].add(spy[0]);
+ spz[1] = spz[1].add(spy[1]);
+
+ return a.newInstance(spz[0].add(spz[1]));
+
+ }
+
+ /** Computes the natural log of a number between 0 and 2.
+ * Let f(x) = ln(x),
+ *
+ * We know that f'(x) = 1/x, thus from Taylor's theorum we have:
+ *
+ * ----- n+1 n
+ * f(x) = \ (-1) (x - 1)
+ * / ---------------- for 1 <= n <= infinity
+ * ----- n
+ *
+ * or
+ * 2 3 4
+ * (x-1) (x-1) (x-1)
+ * ln(x) = (x-1) - ----- + ------ - ------ + ...
+ * 2 3 4
+ *
+ * alternatively,
+ *
+ * 2 3 4
+ * x x x
+ * ln(x+1) = x - - + - - - + ...
+ * 2 3 4
+ *
+ * This series can be used to compute ln(x), but it converges too slowly.
+ *
+ * If we substitute -x for x above, we get
+ *
+ * 2 3 4
+ * x x x
+ * ln(1-x) = -x - - - - - - + ...
+ * 2 3 4
+ *
+ * Note that all terms are now negative. Because the even powered ones
+ * absorbed the sign. Now, subtract the series above from the previous
+ * one to get ln(x+1) - ln(1-x). Note the even terms cancel out leaving
+ * only the odd ones
+ *
+ * 3 5 7
+ * 2x 2x 2x
+ * ln(x+1) - ln(x-1) = 2x + --- + --- + ---- + ...
+ * 3 5 7
+ *
+ * By the property of logarithms that ln(a) - ln(b) = ln (a/b) we have:
+ *
+ * 3 5 7
+ * x+1 / x x x \
+ * ln ----- = 2 * | x + ---- + ---- + ---- + ... |
+ * x-1 \ 3 5 7 /
+ *
+ * But now we want to find ln(a), so we need to find the value of x
+ * such that a = (x+1)/(x-1). This is easily solved to find that
+ * x = (a-1)/(a+1).
+ * @param a number from which logarithm is requested, in split form
+ * @return log(a)
+ */
+ protected static Dfp[] logInternal(final Dfp a[]) {
+
+ /* Now we want to compute x = (a-1)/(a+1) but this is prone to
+ * loss of precision. So instead, compute x = (a/4 - 1/4) / (a/4 + 1/4)
+ */
+ Dfp t = a[0].divide(4).add(a[1].divide(4));
+ Dfp x = t.add(a[0].newInstance("-0.25")).divide(t.add(a[0].newInstance("0.25")));
+
+ Dfp y = new Dfp(x);
+ Dfp num = new Dfp(x);
+ Dfp py = new Dfp(y);
+ int den = 1;
+ for (int i = 0; i < 10000; i++) {
+ num = num.multiply(x);
+ num = num.multiply(x);
+ den = den + 2;
+ t = num.divide(den);
+ y = y.add(t);
+ if (y.equals(py)) {
+ break;
+ }
+ py = new Dfp(y);
+ }
+
+ y = y.multiply(a[0].getTwo());
+
+ return split(y);
+
+ }
+
+ /** Computes x to the y power.<p>
+ *
+ * Uses the following method:<p>
+ *
+ * <ol>
+ * <li> Set u = rint(y), v = y-u
+ * <li> Compute a = v * ln(x)
+ * <li> Compute b = rint( a/ln(2) )
+ * <li> Compute c = a - b*ln(2)
+ * <li> x<sup>y</sup> = x<sup>u</sup> * 2<sup>b</sup> * e<sup>c</sup>
+ * </ol>
+ * if |y| > 1e8, then we compute by exp(y*ln(x)) <p>
+ *
+ * <b>Special Cases</b><p>
+ * <ul>
+ * <li> if y is 0.0 or -0.0 then result is 1.0
+ * <li> if y is 1.0 then result is x
+ * <li> if y is NaN then result is NaN
+ * <li> if x is NaN and y is not zero then result is NaN
+ * <li> if |x| > 1.0 and y is +Infinity then result is +Infinity
+ * <li> if |x| < 1.0 and y is -Infinity then result is +Infinity
+ * <li> if |x| > 1.0 and y is -Infinity then result is +0
+ * <li> if |x| < 1.0 and y is +Infinity then result is +0
+ * <li> if |x| = 1.0 and y is +/-Infinity then result is NaN
+ * <li> if x = +0 and y > 0 then result is +0
+ * <li> if x = +Inf and y < 0 then result is +0
+ * <li> if x = +0 and y < 0 then result is +Inf
+ * <li> if x = +Inf and y > 0 then result is +Inf
+ * <li> if x = -0 and y > 0, finite, not odd integer then result is +0
+ * <li> if x = -0 and y < 0, finite, and odd integer then result is -Inf
+ * <li> if x = -Inf and y > 0, finite, and odd integer then result is -Inf
+ * <li> if x = -0 and y < 0, not finite odd integer then result is +Inf
+ * <li> if x = -Inf and y > 0, not finite odd integer then result is +Inf
+ * <li> if x < 0 and y > 0, finite, and odd integer then result is -(|x|<sup>y</sup>)
+ * <li> if x < 0 and y > 0, finite, and not integer then result is NaN
+ * </ul>
+ * @param x base to be raised
+ * @param y power to which base should be raised
+ * @return x<sup>y</sup>
+ */
+ public static Dfp pow(Dfp x, final Dfp y) {
+
+ // make sure we don't mix number with different precision
+ if (x.getField().getRadixDigits() != y.getField().getRadixDigits()) {
+ x.getField().setIEEEFlagsBits(DfpField.FLAG_INVALID);
+ final Dfp result = x.newInstance(x.getZero());
+ result.nans = Dfp.QNAN;
+ return x.dotrap(DfpField.FLAG_INVALID, POW_TRAP, x, result);
+ }
+
+ final Dfp zero = x.getZero();
+ final Dfp one = x.getOne();
+ final Dfp two = x.getTwo();
+ boolean invert = false;
+ int ui;
+
+ /* Check for special cases */
+ if (y.equals(zero)) {
+ return x.newInstance(one);
+ }
+
+ if (y.equals(one)) {
+ if (!x.equals(x)) {
+ // Test for NaNs
+ x.getField().setIEEEFlagsBits(DfpField.FLAG_INVALID);
+ return x.dotrap(DfpField.FLAG_INVALID, POW_TRAP, x, x);
+ }
+ return x;
+ }
+
+ if (!x.equals(x) || !y.equals(y)) {
+ // Test for NaNs
+ x.getField().setIEEEFlagsBits(DfpField.FLAG_INVALID);
+ return x.dotrap(DfpField.FLAG_INVALID, POW_TRAP, x, x.newInstance((byte)1, (byte) Dfp.QNAN));
+ }
+
+ // X == 0
+ if (x.equals(zero)) {
+ if (Dfp.copysign(one, x).greaterThan(zero)) {
+ // X == +0
+ if (y.greaterThan(zero)) {
+ return x.newInstance(zero);
+ } else {
+ return x.newInstance(x.newInstance((byte)1, (byte)Dfp.INFINITE));
+ }
+ } else {
+ // X == -0
+ if (y.classify() == Dfp.FINITE && y.rint().equals(y) && !y.remainder(two).equals(zero)) {
+ // If y is odd integer
+ if (y.greaterThan(zero)) {
+ return x.newInstance(zero.negate());
+ } else {
+ return x.newInstance(x.newInstance((byte)-1, (byte)Dfp.INFINITE));
+ }
+ } else {
+ // Y is not odd integer
+ if (y.greaterThan(zero)) {
+ return x.newInstance(zero);
+ } else {
+ return x.newInstance(x.newInstance((byte)1, (byte)Dfp.INFINITE));
+ }
+ }
+ }
+ }
+
+ if (x.lessThan(zero)) {
+ // Make x positive, but keep track of it
+ x = x.negate();
+ invert = true;
+ }
+
+ if (x.greaterThan(one) && y.classify() == Dfp.INFINITE) {
+ if (y.greaterThan(zero)) {
+ return y;
+ } else {
+ return x.newInstance(zero);
+ }
+ }
+
+ if (x.lessThan(one) && y.classify() == Dfp.INFINITE) {
+ if (y.greaterThan(zero)) {
+ return x.newInstance(zero);
+ } else {
+ return x.newInstance(Dfp.copysign(y, one));
+ }
+ }
+
+ if (x.equals(one) && y.classify() == Dfp.INFINITE) {
+ x.getField().setIEEEFlagsBits(DfpField.FLAG_INVALID);
+ return x.dotrap(DfpField.FLAG_INVALID, POW_TRAP, x, x.newInstance((byte)1, (byte) Dfp.QNAN));
+ }
+
+ if (x.classify() == Dfp.INFINITE) {
+ // x = +/- inf
+ if (invert) {
+ // negative infinity
+ if (y.classify() == Dfp.FINITE && y.rint().equals(y) && !y.remainder(two).equals(zero)) {
+ // If y is odd integer
+ if (y.greaterThan(zero)) {
+ return x.newInstance(x.newInstance((byte)-1, (byte)Dfp.INFINITE));
+ } else {
+ return x.newInstance(zero.negate());
+ }
+ } else {
+ // Y is not odd integer
+ if (y.greaterThan(zero)) {
+ return x.newInstance(x.newInstance((byte)1, (byte)Dfp.INFINITE));
+ } else {
+ return x.newInstance(zero);
+ }
+ }
+ } else {
+ // positive infinity
+ if (y.greaterThan(zero)) {
+ return x;
+ } else {
+ return x.newInstance(zero);
+ }
+ }
+ }
+
+ if (invert && !y.rint().equals(y)) {
+ x.getField().setIEEEFlagsBits(DfpField.FLAG_INVALID);
+ return x.dotrap(DfpField.FLAG_INVALID, POW_TRAP, x, x.newInstance((byte)1, (byte) Dfp.QNAN));
+ }
+
+ // End special cases
+
+ Dfp r;
+ if (y.lessThan(x.newInstance(100000000)) && y.greaterThan(x.newInstance(-100000000))) {
+ final Dfp u = y.rint();
+ ui = u.intValue();
+
+ final Dfp v = y.subtract(u);
+
+ if (v.unequal(zero)) {
+ final Dfp a = v.multiply(log(x));
+ final Dfp b = a.divide(x.getField().getLn2()).rint();
+
+ final Dfp c = a.subtract(b.multiply(x.getField().getLn2()));
+ r = splitPow(split(x), ui);
+ r = r.multiply(pow(two, b.intValue()));
+ r = r.multiply(exp(c));
+ } else {
+ r = splitPow(split(x), ui);
+ }
+ } else {
+ // very large exponent. |y| > 1e8
+ r = exp(log(x).multiply(y));
+ }
+
+ if (invert) {
+ // if y is odd integer
+ if (y.rint().equals(y) && !y.remainder(two).equals(zero)) {
+ r = r.negate();
+ }
+ }
+
+ return x.newInstance(r);
+
+ }
+
+ /** Computes sin(a) Used when 0 < a < pi/4.
+ * Uses the classic Taylor series. x - x**3/3! + x**5/5! ...
+ * @param a number from which sine is desired, in split form
+ * @return sin(a)
+ */
+ protected static Dfp sinInternal(Dfp a[]) {
+
+ Dfp c = a[0].add(a[1]);
+ Dfp y = c;
+ c = c.multiply(c);
+ Dfp x = y;
+ Dfp fact = a[0].getOne();
+ Dfp py = new Dfp(y);
+
+ for (int i = 3; i < 90; i += 2) {
+ x = x.multiply(c);
+ x = x.negate();
+
+ fact = fact.divide((i-1)*i); // 1 over fact
+ y = y.add(x.multiply(fact));
+ if (y.equals(py))
+ break;
+ py = new Dfp(y);
+ }
+
+ return y;
+
+ }
+
+ /** Computes cos(a) Used when 0 < a < pi/4.
+ * Uses the classic Taylor series for cosine. 1 - x**2/2! + x**4/4! ...
+ * @param a number from which cosine is desired, in split form
+ * @return cos(a)
+ */
+ protected static Dfp cosInternal(Dfp a[]) {
+ final Dfp one = a[0].getOne();
+
+
+ Dfp x = one;
+ Dfp y = one;
+ Dfp c = a[0].add(a[1]);
+ c = c.multiply(c);
+
+ Dfp fact = one;
+ Dfp py = new Dfp(y);
+
+ for (int i = 2; i < 90; i += 2) {
+ x = x.multiply(c);
+ x = x.negate();
+
+ fact = fact.divide((i - 1) * i); // 1 over fact
+
+ y = y.add(x.multiply(fact));
+ if (y.equals(py)) {
+ break;
+ }
+ py = new Dfp(y);
+ }
+
+ return y;
+
+ }
+
+ /** computes the sine of the argument.
+ * @param a number from which sine is desired
+ * @return sin(a)
+ */
+ public static Dfp sin(final Dfp a) {
+ final Dfp pi = a.getField().getPi();
+ final Dfp zero = a.getField().getZero();
+ boolean neg = false;
+
+ /* First reduce the argument to the range of +/- PI */
+ Dfp x = a.remainder(pi.multiply(2));
+
+ /* if x < 0 then apply identity sin(-x) = -sin(x) */
+ /* This puts x in the range 0 < x < PI */
+ if (x.lessThan(zero)) {
+ x = x.negate();
+ neg = true;
+ }
+
+ /* Since sine(x) = sine(pi - x) we can reduce the range to
+ * 0 < x < pi/2
+ */
+
+ if (x.greaterThan(pi.divide(2))) {
+ x = pi.subtract(x);
+ }
+
+ Dfp y;
+ if (x.lessThan(pi.divide(4))) {
+ Dfp c[] = new Dfp[2];
+ c[0] = x;
+ c[1] = zero;
+
+ //y = sinInternal(c);
+ y = sinInternal(split(x));
+ } else {
+ final Dfp c[] = new Dfp[2];
+ final Dfp[] piSplit = a.getField().getPiSplit();
+ c[0] = piSplit[0].divide(2).subtract(x);
+ c[1] = piSplit[1].divide(2);
+ y = cosInternal(c);
+ }
+
+ if (neg) {
+ y = y.negate();
+ }
+
+ return a.newInstance(y);
+
+ }
+
+ /** computes the cosine of the argument.
+ * @param a number from which cosine is desired
+ * @return cos(a)
+ */
+ public static Dfp cos(Dfp a) {
+ final Dfp pi = a.getField().getPi();
+ final Dfp zero = a.getField().getZero();
+ boolean neg = false;
+
+ /* First reduce the argument to the range of +/- PI */
+ Dfp x = a.remainder(pi.multiply(2));
+
+ /* if x < 0 then apply identity cos(-x) = cos(x) */
+ /* This puts x in the range 0 < x < PI */
+ if (x.lessThan(zero)) {
+ x = x.negate();
+ }
+
+ /* Since cos(x) = -cos(pi - x) we can reduce the range to
+ * 0 < x < pi/2
+ */
+
+ if (x.greaterThan(pi.divide(2))) {
+ x = pi.subtract(x);
+ neg = true;
+ }
+
+ Dfp y;
+ if (x.lessThan(pi.divide(4))) {
+ Dfp c[] = new Dfp[2];
+ c[0] = x;
+ c[1] = zero;
+
+ y = cosInternal(c);
+ } else {
+ final Dfp c[] = new Dfp[2];
+ final Dfp[] piSplit = a.getField().getPiSplit();
+ c[0] = piSplit[0].divide(2).subtract(x);
+ c[1] = piSplit[1].divide(2);
+ y = sinInternal(c);
+ }
+
+ if (neg) {
+ y = y.negate();
+ }
+
+ return a.newInstance(y);
+
+ }
+
+ /** computes the tangent of the argument.
+ * @param a number from which tangent is desired
+ * @return tan(a)
+ */
+ public static Dfp tan(final Dfp a) {
+ return sin(a).divide(cos(a));
+ }
+
+ /** computes the arc-tangent of the argument.
+ * @param a number from which arc-tangent is desired
+ * @return atan(a)
+ */
+ protected static Dfp atanInternal(final Dfp a) {
+
+ Dfp y = new Dfp(a);
+ Dfp x = new Dfp(y);
+ Dfp py = new Dfp(y);
+
+ for (int i = 3; i < 90; i += 2) {
+ x = x.multiply(a);
+ x = x.multiply(a);
+ x = x.negate();
+ y = y.add(x.divide(i));
+ if (y.equals(py)) {
+ break;
+ }
+ py = new Dfp(y);
+ }
+
+ return y;
+
+ }
+
+ /** computes the arc tangent of the argument
+ *
+ * Uses the typical taylor series
+ *
+ * but may reduce arguments using the following identity
+ * tan(x+y) = (tan(x) + tan(y)) / (1 - tan(x)*tan(y))
+ *
+ * since tan(PI/8) = sqrt(2)-1,
+ *
+ * atan(x) = atan( (x - sqrt(2) + 1) / (1+x*sqrt(2) - x) + PI/8.0
+ * @param a number from which arc-tangent is desired
+ * @return atan(a)
+ */
+ public static Dfp atan(final Dfp a) {
+ final Dfp zero = a.getField().getZero();
+ final Dfp one = a.getField().getOne();
+ final Dfp[] sqr2Split = a.getField().getSqr2Split();
+ final Dfp[] piSplit = a.getField().getPiSplit();
+ boolean recp = false;
+ boolean neg = false;
+ boolean sub = false;
+
+ final Dfp ty = sqr2Split[0].subtract(one).add(sqr2Split[1]);
+
+ Dfp x = new Dfp(a);
+ if (x.lessThan(zero)) {
+ neg = true;
+ x = x.negate();
+ }
+
+ if (x.greaterThan(one)) {
+ recp = true;
+ x = one.divide(x);
+ }
+
+ if (x.greaterThan(ty)) {
+ Dfp sty[] = new Dfp[2];
+ sub = true;
+
+ sty[0] = sqr2Split[0].subtract(one);
+ sty[1] = sqr2Split[1];
+
+ Dfp[] xs = split(x);
+
+ Dfp[] ds = splitMult(xs, sty);
+ ds[0] = ds[0].add(one);
+
+ xs[0] = xs[0].subtract(sty[0]);
+ xs[1] = xs[1].subtract(sty[1]);
+
+ xs = splitDiv(xs, ds);
+ x = xs[0].add(xs[1]);
+
+ //x = x.subtract(ty).divide(dfp.one.add(x.multiply(ty)));
+ }
+
+ Dfp y = atanInternal(x);
+
+ if (sub) {
+ y = y.add(piSplit[0].divide(8)).add(piSplit[1].divide(8));
+ }
+
+ if (recp) {
+ y = piSplit[0].divide(2).subtract(y).add(piSplit[1].divide(2));
+ }
+
+ if (neg) {
+ y = y.negate();
+ }
+
+ return a.newInstance(y);
+
+ }
+
+ /** computes the arc-sine of the argument.
+ * @param a number from which arc-sine is desired
+ * @return asin(a)
+ */
+ public static Dfp asin(final Dfp a) {
+ return atan(a.divide(a.getOne().subtract(a.multiply(a)).sqrt()));
+ }
+
+ /** computes the arc-cosine of the argument.
+ * @param a number from which arc-cosine is desired
+ * @return acos(a)
+ */
+ public static Dfp acos(Dfp a) {
+ Dfp result;
+ boolean negative = false;
+
+ if (a.lessThan(a.getZero())) {
+ negative = true;
+ }
+
+ a = Dfp.copysign(a, a.getOne()); // absolute value
+
+ result = atan(a.getOne().subtract(a.multiply(a)).sqrt().divide(a));
+
+ if (negative) {
+ result = a.getField().getPi().subtract(result);
+ }
+
+ return a.newInstance(result);
+ }
+
+}
Propchange: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpMath.java
------------------------------------------------------------------------------
svn:eol-style = native
Propchange: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/DfpMath.java
------------------------------------------------------------------------------
svn:keywords = Author Date Id Revision
Added: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/package.html
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/package.html?rev=992697&view=auto
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/package.html (added)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/package.html Sat Sep 4 22:59:21 2010
@@ -0,0 +1,88 @@
+<html>
+<!--
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements. See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with
+ the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ -->
+ <!-- $Revision$ $Date$ -->
+ <body>
+Decimal floating point library for Java
+
+<p>Another floating point class. This one is built using radix 10000
+which is 10<sup>4</sup>, so its almost decimal.</p>
+
+<p>The design goals here are:
+<ol>
+ <li>Decimal math, or close to it</li>
+ <li>Settable precision (but no mix between numbers using different settings)</li>
+ <li>Portability. Code should be keep as portable as possible.</li>
+ <li>Performance</li>
+ <li>Accuracy - Results should always be +/- 1 ULP for basic
+ algebraic operation</li>
+ <li>Comply with IEEE 854-1987 as much as possible.
+ (See IEEE 854-1987 notes below)</li>
+</ol></p>
+
+<p>Trade offs:
+<ol>
+ <li>Memory foot print. I'm using more memory than necessary to
+ represent numbers to get better performance.</li>
+ <li>Digits are bigger, so rounding is a greater loss. So, if you
+ really need 12 decimal digits, better use 4 base 10000 digits
+ there can be one partially filled.</li>
+</ol></p>
+
+<p>Numbers are represented in the following form:
+<pre>
+n = sign × mant × (radix)<sup>exp</sup>;</p>
+</pre>
+where sign is ±1, mantissa represents a fractional number between
+zero and one. mant[0] is the least significant digit.
+exp is in the range of -32767 to 32768</p>
+
+<p>IEEE 854-1987 Notes and differences</p>
+
+<p>IEEE 854 requires the radix to be either 2 or 10. The radix here is
+10000, so that requirement is not met, but it is possible that a
+subclassed can be made to make it behave as a radix 10
+number. It is my opinion that if it looks and behaves as a radix
+10 number then it is one and that requirement would be met.</p>
+
+<p>The radix of 10000 was chosen because it should be faster to operate
+on 4 decimal digits at once instead of one at a time. Radix 10 behavior
+can be realized by add an additional rounding step to ensure that
+the number of decimal digits represented is constant.</p>
+
+<p>The IEEE standard specifically leaves out internal data encoding,
+so it is reasonable to conclude that such a subclass of this radix
+10000 system is merely an encoding of a radix 10 system.</p>
+
+<p>IEEE 854 also specifies the existence of "sub-normal" numbers. This
+class does not contain any such entities. The most significant radix
+10000 digit is always non-zero. Instead, we support "gradual underflow"
+by raising the underflow flag for numbers less with exponent less than
+expMin, but don't flush to zero until the exponent reaches MIN_EXP-digits.
+Thus the smallest number we can represent would be:
+1E(-(MIN_EXP-digits-1)*4), eg, for digits=5, MIN_EXP=-32767, that would
+be 1e-131092.</p>
+
+<p>IEEE 854 defines that the implied radix point lies just to the right
+of the most significant digit and to the left of the remaining digits.
+This implementation puts the implied radix point to the left of all
+digits including the most significant one. The most significant digit
+here is the one just to the right of the radix point. This is a fine
+detail and is really only a matter of definition. Any side effects of
+this can be rendered invisible by a subclass.</p>
+ </body>
+</html>
Propchange: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/package.html
------------------------------------------------------------------------------
svn:eol-style = native
Propchange: commons/proper/math/trunk/src/main/java/org/apache/commons/math/dfp/package.html
------------------------------------------------------------------------------
svn:keywords = Author Date Id Revision
Modified: commons/proper/math/trunk/src/site/xdoc/changes.xml
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/site/xdoc/changes.xml?rev=992697&r1=992696&r2=992697&view=diff
==============================================================================
--- commons/proper/math/trunk/src/site/xdoc/changes.xml (original)
+++ commons/proper/math/trunk/src/site/xdoc/changes.xml Sat Sep 4 22:59:21 2010
@@ -71,6 +71,13 @@ The <action> type attribute can be add,u
</action>
</release>
<release version="2.2" date="TBD" description="TBD">
+ <action dev="luc" type="fix" issue="MATH-412" due-to="Bill Rossi">
+ Added the dfp library providing arbitrary precision floating point computation in the spirit of
+ IEEE 854-1987 (not exactly as it uses base 1000 instead of base 10). In addition to finite numbers,
+ infinities and NaNs are available (but there are no subnormals). All IEEE 854-1987 rounding modes and
+ signaling flags are supported. The available operations are +, -, *, / and the available functions
+ are sqrt, sin, cos, tan, asin, acos, atan, exp, log.
+ </action>
<action dev="luc" type="fix" issue="MATH-375" due-to="Bill Rossi">
Added faster and more accurate version of traditional mathematical functions in a FastMath
class intended to be a drop-in replacement for java.util.Math at source-level. Some functions
Added: commons/proper/math/trunk/src/test/java/org/apache/commons/math/dfp/Decimal10.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/test/java/org/apache/commons/math/dfp/Decimal10.java?rev=992697&view=auto
==============================================================================
--- commons/proper/math/trunk/src/test/java/org/apache/commons/math/dfp/Decimal10.java (added)
+++ commons/proper/math/trunk/src/test/java/org/apache/commons/math/dfp/Decimal10.java Sat Sep 4 22:59:21 2010
@@ -0,0 +1,90 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.math.dfp;
+
+public class Decimal10 extends DfpDec {
+
+ Decimal10(final DfpField factory) {
+ super(factory);
+ }
+
+ Decimal10(final DfpField factory, final byte x) {
+ super(factory, x);
+ }
+
+ Decimal10(final DfpField factory, final int x) {
+ super(factory, x);
+ }
+
+ Decimal10(final DfpField factory, final long x) {
+ super(factory, x);
+ }
+
+ Decimal10(final DfpField factory, final double x) {
+ super(factory, x);
+ }
+
+ public Decimal10(final Dfp d) {
+ super(d);
+ }
+
+ public Decimal10(final DfpField factory, final String s) {
+ super(factory, s);
+ }
+
+ protected Decimal10(final DfpField factory, final byte sign, final byte nans) {
+ super(factory, sign, nans);
+ }
+
+ public Dfp newInstance() {
+ return new Decimal10(getField());
+ }
+
+ public Dfp newInstance(final byte x) {
+ return new Decimal10(getField(), x);
+ }
+
+ public Dfp newInstance(final int x) {
+ return new Decimal10(getField(), x);
+ }
+
+ public Dfp newInstance(final long x) {
+ return new Decimal10(getField(), x);
+ }
+
+ public Dfp newInstance(final double x) {
+ return new Decimal10(getField(), x);
+ }
+
+ public Dfp newInstance(final Dfp d) {
+ return new Decimal10(d);
+ }
+
+ public Dfp newInstance(final String s) {
+ return new Decimal10(getField(), s);
+ }
+
+ public Dfp newInstance(final byte sign, final byte nans) {
+ return new Decimal10(getField(), sign, nans);
+ }
+
+ protected int getDecimalDigits() {
+ return 10;
+ }
+
+}
Propchange: commons/proper/math/trunk/src/test/java/org/apache/commons/math/dfp/Decimal10.java
------------------------------------------------------------------------------
svn:eol-style = native
Propchange: commons/proper/math/trunk/src/test/java/org/apache/commons/math/dfp/Decimal10.java
------------------------------------------------------------------------------
svn:keywords = Author Date Id Revision