commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From luc.maison...@free.fr
Subject Re: svn commit: r780974 - /commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java
Date Tue, 02 Jun 2009 09:14:34 GMT
Hello,

This change has been implemented as general utility functions and is
used for now only in the linear optimizer package, see LinearObjectiveFunction and LinearConstraint
classes (it should fix a recent Gump failure).

Do others think using these new methods should be generalized to other classes that have RealVector/RealMatrix
fields ?

Luc

----- luc@apache.org a écrit :

> Author: luc
> Date: Tue Jun  2 09:03:31 2009
> New Revision: 780974
> 
> URL: http://svn.apache.org/viewvc?rev=780974&view=rev
> Log:
> added utility methods to help serialize/deserialize classes that
> have RealVector/RealMatrix fields (possibly final) since the
> top level interfaces are not serializable anymore
> 
> Modified:
>    
> commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java
> 
> Modified:
> commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java
> URL:
> http://svn.apache.org/viewvc/commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java?rev=780974&r1=780973&r2=780974&view=diff
> ==============================================================================
> ---
> commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java
> (original)
> +++
> commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java
> Tue Jun  2 09:03:31 2009
> @@ -17,6 +17,9 @@
>  
>  package org.apache.commons.math.linear;
>  
> +import java.io.IOException;
> +import java.io.ObjectInputStream;
> +import java.io.ObjectOutputStream;
>  import java.lang.reflect.Array;
>  import java.math.BigDecimal;
>  import java.util.Arrays;
> @@ -717,4 +720,214 @@
>  
>      }
>  
> +    /** Serialize a {@link RealVector}.
> +     * <p>
> +     * This method is intended to be called from within a private
> +     * <code>writeObject</code> method (after a call to
> +     * <code>oos.defaultWriteObject()</code>) in a class that has a
> +     * {@link RealVector} field, which should be declared
> <code>transient</code>.
> +     * This way, the default handling does not serialize the vector
> (the {@link
> +     * RealVector} interface is not serializable by default) but this
> method does
> +     * serialize it specifically.
> +     * </p>
> +     * <p>
> +     * The following example shows how a simple class with a name and
> a real vector
> +     * should be written:
> +     * <pre><code>
> +     * public class NamedVector implements Serializable {
> +     *
> +     *     private final String name;
> +     *     private final transient RealVector coefficients;
> +     *
> +     *     // omitted constructors, getters ...
> +     *
> +     *     private void writeObject(ObjectOutputStream oos) throws
> IOException {
> +     *         oos.defaultWriteObject();  // takes care of name
> field
> +     *         MatrixUtils.serializeRealVector(coefficients, oos);
> +     *     }
> +     *
> +     *     private void readObject(ObjectInputStream ois) throws
> ClassNotFoundException, IOException {
> +     *         ois.defaultReadObject();  // takes care of name field
> +     *         MatrixUtils.deserializeRealVector(this,
> "coefficients", ois);
> +     *     }
> +     *
> +     * }
> +     * </code></pre>
> +     * </p>
> +     * 
> +     * @param vector real vector to serialize
> +     * @param oos stream where the real vector should be written
> +     * @exception IOException if object cannot be written to stream
> +     * @see #deserializeRealVector(Object, String,
> ObjectInputStream)
> +     */
> +    public static void serializeRealVector(final RealVector vector,
> +                                           final ObjectOutputStream
> oos)
> +        throws IOException {
> +        final int n = vector.getDimension();
> +        oos.writeInt(n);
> +        for (int i = 0; i < n; ++i) {
> +            oos.writeDouble(vector.getEntry(i));
> +        }
> +    }
> +
> +    /** Deserialize  a {@link RealVector} field in a class.
> +     * <p>
> +     * This method is intended to be called from within a private
> +     * <code>readObject</code> method (after a call to
> +     * <code>ois.defaultReadObject()</code>) in a class that has a
> +     * {@link RealVector} field, which should be declared
> <code>transient</code>.
> +     * This way, the default handling does not deserialize the vector
> (the {@link
> +     * RealVector} interface is not serializable by default) but this
> method does
> +     * deserialize it specifically.
> +     * </p>
> +     * @param instance instance in which the field must be set up
> +     * @param fieldName name of the field within the class (may be
> private and final)
> +     * @param ois stream from which the real vector should be read
> +     * @exception ClassNotFoundException if a class in the stream
> cannot be found
> +     * @exception IOException if object cannot be read from the
> stream
> +     * @see #serializeRealVector(RealVector, ObjectOutputStream)
> +     */
> +    public static void deserializeRealVector(final Object instance,
> +                                             final String fieldName,
> +                                             final ObjectInputStream
> ois)
> +      throws ClassNotFoundException, IOException {
> +        try {
> +
> +            // read the vector data
> +            final int n = ois.readInt();
> +            final double[] data = new double[n];
> +            for (int i = 0; i < n; ++i) {
> +                data[i] = ois.readDouble();
> +            }
> +
> +            // create the instance
> +            final RealVector vector = new RealVectorImpl(data,
> false);
> +
> +            // set up the field
> +            final java.lang.reflect.Field f =
> +                instance.getClass().getDeclaredField(fieldName);
> +            f.setAccessible(true);
> +            f.set(instance, vector);
> +
> +        } catch (NoSuchFieldException nsfe) {
> +            IOException ioe = new IOException();
> +            ioe.initCause(nsfe);
> +            throw ioe;
> +        } catch (IllegalAccessException iae) {
> +            IOException ioe = new IOException();
> +            ioe.initCause(iae);
> +            throw ioe;
> +        }
> +
> +    }
> +
> +    /** Serialize a {@link RealMatrix}.
> +     * <p>
> +     * This method is intended to be called from within a private
> +     * <code>writeObject</code> method (after a call to
> +     * <code>oos.defaultWriteObject()</code>) in a class that has a
> +     * {@link RealMatrix} field, which should be declared
> <code>transient</code>.
> +     * This way, the default handling does not serialize the matrix
> (the {@link
> +     * RealMatrix} interface is not serializable by default) but this
> method does
> +     * serialize it specifically.
> +     * </p>
> +     * <p>
> +     * The following example shows how a simple class with a name and
> a real matrix
> +     * should be written:
> +     * <pre><code>
> +     * public class NamedMatrix implements Serializable {
> +     *
> +     *     private final String name;
> +     *     private final transient RealMatrix coefficients;
> +     *
> +     *     // omitted constructors, getters ...
> +     *
> +     *     private void writeObject(ObjectOutputStream oos) throws
> IOException {
> +     *         oos.defaultWriteObject();  // takes care of name
> field
> +     *         MatrixUtils.serializeRealMatrix(coefficients, oos);
> +     *     }
> +     *
> +     *     private void readObject(ObjectInputStream ois) throws
> ClassNotFoundException, IOException {
> +     *         ois.defaultReadObject();  // takes care of name field
> +     *         MatrixUtils.deserializeRealMatrix(this,
> "coefficients", ois);
> +     *     }
> +     *
> +     * }
> +     * </code></pre>
> +     * </p>
> +     * 
> +     * @param matrix real matrix to serialize
> +     * @param oos stream where the real matrix should be written
> +     * @exception IOException if object cannot be written to stream
> +     * @see #deserializeRealMatrix(Object, String,
> ObjectInputStream)
> +     */
> +    public static void serializeRealMatrix(final RealMatrix matrix,
> +                                           final ObjectOutputStream
> oos)
> +        throws IOException {
> +        final int n = matrix.getRowDimension();
> +        final int m = matrix.getColumnDimension();
> +        oos.writeInt(n);
> +        oos.writeInt(m);
> +        for (int i = 0; i < n; ++i) {
> +            for (int j = 0; j < m; ++j) {
> +                oos.writeDouble(matrix.getEntry(i, j));
> +            }
> +        }
> +    }
> +
> +    /** Deserialize  a {@link RealMatrix} field in a class.
> +     * <p>
> +     * This method is intended to be called from within a private
> +     * <code>readObject</code> method (after a call to
> +     * <code>ois.defaultReadObject()</code>) in a class that has a
> +     * {@link RealMatrix} field, which should be declared
> <code>transient</code>.
> +     * This way, the default handling does not deserialize the matrix
> (the {@link
> +     * RealMatrix} interface is not serializable by default) but this
> method does
> +     * deserialize it specifically.
> +     * </p>
> +     * @param instance instance in which the field must be set up
> +     * @param fieldName name of the field within the class (may be
> private and final)
> +     * @param ois stream from which the real matrix should be read
> +     * @exception ClassNotFoundException if a class in the stream
> cannot be found
> +     * @exception IOException if object cannot be read from the
> stream
> +     * @see #serializeVector(RealVector, ObjectOutputStream)
> +     */
> +    public static void deserializeRealMatrix(final Object instance,
> +                                             final String fieldName,
> +                                             final ObjectInputStream
> ois)
> +      throws ClassNotFoundException, IOException {
> +        try {
> +
> +            // read the matrix data
> +            final int n = ois.readInt();
> +            final int m = ois.readInt();
> +            final double[][] data = new double[n][m];
> +            for (int i = 0; i < n; ++i) {
> +                final double[] dataI = data[i];
> +                for (int j = 0; j < m; ++j) {
> +                    dataI[j] = ois.readDouble();
> +                }
> +            }
> +
> +            // create the instance
> +            final RealMatrix matrix = new RealMatrixImpl(data,
> false);
> +
> +            // set up the field
> +            final java.lang.reflect.Field f =
> +                instance.getClass().getDeclaredField(fieldName);
> +            f.setAccessible(true);
> +            f.set(instance, matrix);
> +
> +        } catch (NoSuchFieldException nsfe) {
> +            IOException ioe = new IOException();
> +            ioe.initCause(nsfe);
> +            throw ioe;
> +        } catch (IllegalAccessException iae) {
> +            IOException ioe = new IOException();
> +            ioe.initCause(iae);
> +            throw ioe;
> +        }
> +
> +    }
> +
>  }

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
For additional commands, e-mail: dev-help@commons.apache.org


Mime
View raw message