Added the generic Field/FieldElement interfaces on top

of existing Complex, Fraction and BigFraction
Added a new BigReal class wrapping a BidDecimal and implementing FieldElement

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@766483 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/math/complex/Complex.java

@@ -17,10 +17,10 @@
 
 package org.apache.commons.math.complex;
 
-import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.commons.math.FieldElement;
 import org.apache.commons.math.MathRuntimeException;
 import org.apache.commons.math.util.MathUtils;
 
@@ -40,11 +40,11 @@ import org.apache.commons.math.util.MathUtils;
  *
  * @version $Revision$ $Date$
  */
-public class Complex implements Serializable  {
+public class Complex implements FieldElement<Complex>  {
 
     /** Serializable version identifier */
-    private static final long serialVersionUID = -6530173849413811929L;
-    
+    private static final long serialVersionUID = -6195664516687396620L;
+
     /** The square root of -1. A number representing "0.0 + 1.0i" */    
     public static final Complex I = new Complex(0.0, 1.0);
     
@@ -953,4 +953,10 @@ public class Complex implements Serializable  {
     protected Complex createComplex(double real, double imaginary) {
         return new Complex(real, imaginary);
     }
+
+    /** {@inheritDoc} */
+    public ComplexField getField() {
+        return ComplexField.getInstance();
+    }
+
 }

src/java/org/apache/commons/math/complex/ComplexField.java

@@ -0,0 +1,66 @@
+/*
+ * 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.complex;
+
+import org.apache.commons.math.Field;
+
+/**
+ * Representation of the complex numbers field.
+ * <p>
+ * This class is a singleton.
+ * </p>
+ * @see Complex
+ * @version $Revision$ $Date$
+ * @since 2.0
+ */
+public class ComplexField implements Field<Complex>  {
+
+    /** Serializable version identifier. */
+    private static final long serialVersionUID = -6130362688700788798L;
+
+    /** Private constructor for the singleton.
+     */
+    private ComplexField() {
+    }
+
+    /** Get the unique instance.
+     * @return the unique instance
+     */
+    public static ComplexField getInstance() {
+        return LazyHolder.INSTANCE;
+    }
+
+    /** {@inheritDoc} */
+    public Complex getOne() {
+        return Complex.ONE;
+    }
+
+    /** {@inheritDoc} */
+    public Complex getZero() {
+        return Complex.ZERO;
+    }
+
+    /** Holder for the instance.
+     * <p>We use here the Initialization On Demand Holder Idiom.</p>
+     */
+    private static class LazyHolder {
+        /** Cached field instance. */
+        private static final ComplexField INSTANCE = new ComplexField();
+    }
+
+}

src/java/org/apache/commons/math/fraction/BigFraction.java

@@ -19,6 +19,7 @@ package org.apache.commons.math.fraction;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 
+import org.apache.commons.math.FieldElement;
 import org.apache.commons.math.MathRuntimeException;
 import org.apache.commons.math.util.MathUtils;
 
@@ -29,7 +30,7 @@ import org.apache.commons.math.util.MathUtils;
  * @version $Revision$ $Date$
  * @since 2.0
  */
-public class BigFraction extends Number implements Comparable<BigFraction> {
+public class BigFraction extends Number implements FieldElement<BigFraction>, Comparable<BigFraction> {
 
     /** A fraction representing "2 / 1". */
     public static final BigFraction TWO = new BigFraction(2);
@@ -74,7 +75,7 @@ public class BigFraction extends Number implements Comparable<BigFraction> {
     public static final BigFraction TWO_THIRDS = new BigFraction(2, 3);
 
     /** Serializable version identifier. */
-    private static final long serialVersionUID = -130662482360701382L;
+    private static final long serialVersionUID = -5630213147331578515L;
 
     /** <code>BigInteger</code> representation of 100. */
     private static final BigInteger ONE_HUNDRED_DOUBLE = BigInteger.valueOf(100);
@@ -1119,4 +1120,10 @@ public class BigFraction extends Number implements Comparable<BigFraction> {
         }
         return str;
     }
+
+    /** {@inheritDoc} */
+    public BigFractionField getField() {
+        return BigFractionField.getInstance();
+    }
+
 }

src/java/org/apache/commons/math/fraction/BigFractionField.java

@@ -0,0 +1,66 @@
+/*
+ * 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.fraction;
+
+import org.apache.commons.math.Field;
+
+/**
+ * Representation of the fractional numbers  without any overflow field.
+ * <p>
+ * This class is a singleton.
+ * </p>
+ * @see Fraction
+ * @version $Revision$ $Date$
+ * @since 2.0
+ */
+public class BigFractionField implements Field<BigFraction>  {
+
+    /** Serializable version identifier */
+    private static final long serialVersionUID = -1699294557189741703L;
+
+    /** Private constructor for the singleton.
+     */
+    private BigFractionField() {
+    }
+
+    /** Get the unique instance.
+     * @return the unique instance
+     */
+    public static BigFractionField getInstance() {
+        return LazyHolder.INSTANCE;
+    }
+
+    /** {@inheritDoc} */
+    public BigFraction getOne() {
+        return BigFraction.ONE;
+    }
+
+    /** {@inheritDoc} */
+    public BigFraction getZero() {
+        return BigFraction.ZERO;
+    }
+
+    /** Holder for the instance.
+     * <p>We use here the Initialization On Demand Holder Idiom.</p>
+     */
+    private static class LazyHolder {
+        /** Cached field instance. */
+        private static final BigFractionField INSTANCE = new BigFractionField();
+    }
+
+}

src/java/org/apache/commons/math/fraction/Fraction.java

@@ -18,6 +18,7 @@ package org.apache.commons.math.fraction;
 
 import java.math.BigInteger;
 
+import org.apache.commons.math.FieldElement;
 import org.apache.commons.math.MathRuntimeException;
 import org.apache.commons.math.util.MathUtils;
 
@@ -27,7 +28,7 @@ import org.apache.commons.math.util.MathUtils;
  * @since 1.1
  * @version $Revision$ $Date$
  */
-public class Fraction extends Number implements Comparable<Fraction> {
+public class Fraction extends Number implements FieldElement<Fraction>, Comparable<Fraction> {
 
     /** A fraction representing "2 / 1". */
     public static final Fraction TWO = new Fraction(2, 1);
@@ -72,7 +73,7 @@ public class Fraction extends Number implements Comparable<Fraction> {
     public static final Fraction MINUS_ONE = new Fraction(-1, 1);
 
     /** Serializable version identifier */
-    private static final long serialVersionUID = 3071409609509774764L;
+    private static final long serialVersionUID = 3698073679419233275L;
 
     /** The denominator. */
     private final int denominator;
@@ -649,4 +650,9 @@ public class Fraction extends Number implements Comparable<Fraction> {
         return str;
     }
 
+    /** {@inheritDoc} */
+    public FractionField getField() {
+        return FractionField.getInstance();
+    }
+
 }

src/java/org/apache/commons/math/fraction/FractionField.java

@@ -0,0 +1,66 @@
+/*
+ * 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.fraction;
+
+import org.apache.commons.math.Field;
+
+/**
+ * Representation of the fractional numbers field.
+ * <p>
+ * This class is a singleton.
+ * </p>
+ * @see Fraction
+ * @version $Revision$ $Date$
+ * @since 2.0
+ */
+public class FractionField implements Field<Fraction>  {
+
+    /** Serializable version identifier */
+    private static final long serialVersionUID = -1257768487499119313L;
+
+    /** Private constructor for the singleton.
+     */
+    private FractionField() {
+    }
+
+    /** Get the unique instance.
+     * @return the unique instance
+     */
+    public static FractionField getInstance() {
+        return LazyHolder.INSTANCE;
+    }
+
+    /** {@inheritDoc} */
+    public Fraction getOne() {
+        return Fraction.ONE;
+    }
+
+    /** {@inheritDoc} */
+    public Fraction getZero() {
+        return Fraction.ZERO;
+    }
+
+    /** Holder for the instance.
+     * <p>We use here the Initialization On Demand Holder Idiom.</p>
+     */
+    private static class LazyHolder {
+        /** Cached field instance. */
+        private static final FractionField INSTANCE = new FractionField();
+    }
+
+}

src/java/org/apache/commons/math/util/BigReal.java

@@ -0,0 +1,213 @@
+/*
+ * 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.util;
+
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.math.MathContext;
+
+import org.apache.commons.math.Field;
+import org.apache.commons.math.FieldElement;
+
+/**
+ * Arbitrary precision decimal number.
+ * <p>
+ * This class is a simple wrapper around the standard <code>BigDecimal</code>
+ * in order to implement the {@link FieldElement} interface.
+ * </p>
+ * @since 2.0
+ * @version $Revision$ $Date$
+ */
+public class BigReal implements FieldElement<BigReal>, Comparable<BigReal> {
+
+    /** Serializable version identifier. */
+    private static final long serialVersionUID = 7887631840434052850L;
+
+    /** A big real representing 0. */
+    public static final BigReal ZERO = new BigReal(BigDecimal.ZERO);
+
+    /** A big real representing 1. */
+    public static final BigReal ONE = new BigReal(BigDecimal.ONE);
+
+    /** Underlying BigDecimal. */
+    private final BigDecimal d;
+
+    /** Build an instance from a BigDecimal.
+     * @param val value of the instance
+     */
+    public BigReal(BigDecimal val) {
+        d =  val;
+    }
+
+    /** Build an instance from a BigInteger.
+     * @param val value of the instance
+     */
+    public BigReal(BigInteger val) {
+        d = new BigDecimal(val);
+    }
+
+    /** Build an instance from an unscaled BigInteger.
+     * @param unscaledVal unscaled value
+     * @param scale scale to use
+     */
+    public BigReal(BigInteger unscaledVal, int scale) {
+        d = new BigDecimal(unscaledVal, scale);
+    }
+
+    /** Build an instance from an unscaled BigInteger.
+     * @param unscaledVal unscaled value
+     * @param scale scale to use
+     * @param mc to used
+     */
+    public BigReal(BigInteger unscaledVal, int scale, MathContext mc) {
+        d = new BigDecimal(unscaledVal, scale, mc);
+    }
+
+    /** Build an instance from a BigInteger.
+     * @param val value of the instance
+     * @param mc context to use
+     */
+    public BigReal(BigInteger val, MathContext mc) {
+        d = new BigDecimal(val, mc);
+    }
+
+    /** Build an instance from a characters representation.
+     * @param in character representation of the value
+     */
+    public BigReal(char[] in) {
+        d = new BigDecimal(in);
+    }
+
+    /** Build an instance from a characters representation.
+     * @param in character representation of the value
+     * @param offset offset of the first character to analyze
+     * @param len length of the array slice to analyze
+     */
+    public BigReal(char[] in, int offset, int len) {
+        d = new BigDecimal(in, offset, len);
+    }
+
+    /** Build an instance from a characters representation.
+     * @param in character representation of the value
+     * @param offset offset of the first character to analyze
+     * @param len length of the array slice to analyze
+     * @param mc context to use
+     */
+    public BigReal(char[] in, int offset, int len, MathContext mc) {
+        d = new BigDecimal(in, offset, len, mc);
+    }
+
+    /** Build an instance from a characters representation.
+     * @param in character representation of the value
+     * @param mc context to use
+     */
+    public BigReal(char[] in, MathContext mc) {
+        d = new BigDecimal(in, mc);
+    }
+
+    /** Build an instance from a double.
+     * @param val value of the instance
+     */
+    public BigReal(double val) {
+        d = new BigDecimal(val);
+    }
+
+    /** Build an instance from a double.
+     * @param val value of the instance
+     * @param mc context to use
+     */
+    public BigReal(double val, MathContext mc) {
+        d = new BigDecimal(val, mc);
+    }
+
+    /** Build an instance from an int.
+     * @param val value of the instance
+     */
+    public BigReal(int val) {
+        d = new BigDecimal(val);
+    }
+
+    /** Build an instance from an int.
+     * @param val value of the instance
+     * @param mc context to use
+     */
+    public BigReal(int val, MathContext mc) {
+        d = new BigDecimal(val, mc);
+    }
+
+    /** Build an instance from a long.
+     * @param val value of the instance
+     */
+    public BigReal(long val) {
+        d = new BigDecimal(val);
+    }
+
+    /** Build an instance from a long.
+     * @param val value of the instance
+     * @param mc context to use
+     */
+    public BigReal(long val, MathContext mc) {
+        d = new BigDecimal(val, mc);
+    }
+
+    /** Build an instance from a String representation.
+     * @param val character representation of the value
+     */
+    public BigReal(String val) {
+        d = new BigDecimal(val);
+    }
+
+    /** Build an instance from a String representation.
+     * @param val character representation of the value
+     * @param mc context to use
+     */
+    public BigReal(String val, MathContext mc)  {
+        d = new BigDecimal(val, mc);
+    }
+
+    /** {@inheritDoc} */
+    public BigReal add(BigReal a) {
+        return new BigReal(d.add(a.d));
+    }
+
+    /** {@inheritDoc} */
+    public BigReal subtract(BigReal a) {
+        return new BigReal(d.subtract(a.d));
+    }
+
+    /** {@inheritDoc} */
+    public BigReal divide(BigReal a) throws ArithmeticException {
+        return new BigReal(d.divide(a.d));
+    }
+
+    /** {@inheritDoc} */
+    public BigReal multiply(BigReal a) {
+        return new BigReal(d.multiply(a.d));
+    }
+
+    /** {@inheritDoc} */
+    public int compareTo(BigReal a) {
+        return d.compareTo(a.d);
+    }
+
+    /** {@inheritDoc} */
+    public Field<BigReal> getField() {
+        return BigRealField.getInstance();
+    }
+
+}

src/java/org/apache/commons/math/util/BigRealField.java

@@ -0,0 +1,66 @@
+/*
+ * 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.util;
+
+import org.apache.commons.math.Field;
+
+/**
+ * Representation of real numbers with arbitrary precision field.
+ * <p>
+ * This class is a singleton.
+ * </p>
+ * @see BigReal
+ * @version $Revision$ $Date$
+ * @since 2.0
+ */
+public class BigRealField implements Field<BigReal>  {
+
+    /** Serializable version identifier */
+    private static final long serialVersionUID = 4756431066541037559L;
+
+    /** Private constructor for the singleton.
+     */
+    private BigRealField() {
+    }
+
+    /** Get the unique instance.
+     * @return the unique instance
+     */
+    public static BigRealField getInstance() {
+        return LazyHolder.INSTANCE;
+    }
+
+    /** {@inheritDoc} */
+    public BigReal getOne() {
+        return BigReal.ONE;
+    }
+
+    /** {@inheritDoc} */
+    public BigReal getZero() {
+        return BigReal.ZERO;
+    }
+
+    /** Holder for the instance.
+     * <p>We use here the Initialization On Demand Holder Idiom.</p>
+     */
+    private static class LazyHolder {
+        /** Cached field instance. */
+        private static final BigRealField INSTANCE = new BigRealField();
+    }
+
+}

src/site/xdoc/changes.xml

@@ -39,6 +39,11 @@ The <action> type attribute can be add,update,fix,remove.
   </properties>
   <body>
     <release version="2.0" date="TBD" description="TBD">
+      <action dev="luc" type="add" >
+        Added general Field and FieldElement interfaces to allow generic algorithms
+        to operate on fields. The library already provides several implementations:
+        Complex, Fraction, BigFraction and BigReal
+      </action>
       <action dev="luc" type="fix" issue="MATH-257" due-to="Sebb">
         Fixed inconsistent access to multidimensional array in FastFourierTransformer
       </action>