Prime decomposition example.

Enlarging the Java VM's heap space.

Doc/Sd1/appendix.xml

@@ -481,6 +481,103 @@ public class FactorTest {
           <para>Check for second prime factor 3 of frequency 1.</para>
         </callout>
       </calloutlist>
+
+      <para>For better illustration we provide the following example:</para>
+
+      <programlisting language="java">public class Driver {
+
+   /**
+    * @param args Unused
+    */
+   public static void main( String[] args ) {
+      
+      final Sieve sieve = new Sieve(Integer.MAX_VALUE);
+
+      
+      int value = Integer.MAX_VALUE;
+      System.out.println("Value " + value + " is " + 
+        (sieve.isPrime(value)? "" : "not") + " prime.");
+
+      value--; // Even Value
+      
+      System.out.println("Value " + value + " is " + 
+            (sieve.isPrime(value)? "" : "not") + " prime.");
+
+      value --; // Non-prime as well.
+      System.out.println("Value " + value + " is " + 
+            (sieve.isPrime(value)? "" : "not") + " prime.");
+
+
+      value = Integer.MAX_VALUE - 1;
+      final PrimeFrequencySet pfs = sieve.getPrimeFactors(value);
+      
+      System.out.print(value + " = ");
+      String separator = "";
+      for (PrimeFrequency pf : pfs.get()) {
+         for (int i = 0; i &lt; pf.getFrequency(); i++) {
+            System.out.print(separator + pf.prime);
+            separator = " * ";
+         }
+      }
+      System.out.println();
+   }
+}</programlisting>
+
+      <para>This yields the following output:</para>
+
+      <programlisting language="none">Value 2147483647 is  prime.
+Value 2147483646 is not prime.
+Value 2147483645 is not prime.
+2147483646 = 2 * 3 * 3 * 7 * 11 * 31 * 151 * 331</programlisting>
+
+      <para>Depending on your implementation you may encounter the following
+      heap memory related error:</para>
+
+      <programlisting language="none">Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
+	at de.hdm_stuttgart.mi.prim.sieve.Sieve.initSieve(Sieve.java:75)
+	at de.hdm_stuttgart.mi.prim.sieve.Sieve.&lt;init&gt;(Sieve.java:60)
+	at de.hdm_stuttgart.mi.prim.Driver.main(Driver.java:19)</programlisting>
+
+      <para>The <xref linkend="glo_Java"/> virtual machine by default may not
+      provide enough heap space. You may enlarge the default allocation by
+      setting the <option>-Xmx</option>. Eclipse provides a convenient way by
+      means of a run time configuration (Menu Run --&gt; Run
+      Configurations):</para>
+
+      <informalfigure>
+        <mediaobject>
+          <imageobject>
+            <imagedata fileref="Ref/Screen/primDriverRunConfigOverview.bmp"/>
+          </imageobject>
+        </mediaobject>
+      </informalfigure>
+
+      <para>Clicking the <quote>Arguments</quote> tab allows for setting the
+      respective VM heap setting:</para>
+
+      <informalfigure>
+        <mediaobject>
+          <imageobject>
+            <imagedata fileref="Ref/Screen/primDriverRunConfigVmOptions.bmp"/>
+          </imageobject>
+        </mediaobject>
+      </informalfigure>
+
+      <para>This allows for running your application with a maximum of 4
+      gigabytes heap space.</para>
+
+      <para>With respect to automated unit testing (<command>mvn</command>
+      <option>test</option>)you may want to set the same value in you
+      <filename>pom.xml</filename> file</para>
+
+      <programlisting language="xml">&lt;plugin&gt;
+    &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
+    &lt;artifactId&gt;maven-surefire-plugin&lt;/artifactId&gt;
+    &lt;version&gt;2.19&lt;/version&gt;
+    &lt;configuration&gt;
+      <emphasis role="bold">&lt;argLine&gt;-Xmx4G&lt;/argLine&gt;</emphasis>
+  &lt;/configuration&gt;
+&lt;/plugin&gt;</programlisting>
     </section>
   </section>
 </appendix>