Added checkstyle filter for exceptional catch of RuntimeException.

These catch occur in multi-start optimizers. The exceptions are caught
and stored, and if all restarts fail, then one of the stored
RuntimeException is rethrown. The purpose of multi-start is both to
allow some trials to fail and to avoid being trapped in a local
extremum. Catching RuntimeException is therefore mandatory here, and not
dangerous since we rethrow them as needed.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1179947 13f79535-47bb-0310-9956-ffa450edef68

checkstyle.xml

@@ -178,6 +178,11 @@
     <property name="onCommentFormat"  value="CHECKSTYLE\: resume MultipleVariableDeclarations"/>
     <property name="checkFormat"      value="MultipleVariableDeclarations"/>
   </module>
+  <module name="SuppressionCommentFilter">
+    <property name="offCommentFormat" value="CHECKSTYLE\: stop IllegalCatch"/>
+    <property name="onCommentFormat"  value="CHECKSTYLE\: resume IllegalCatch"/>
+    <property name="checkFormat"      value="IllegalCatch"/>
+  </module>
 
 </module>
 

src/main/java/org/apache/commons/math/optimization/BaseMultiStartMultivariateRealOptimizer.java

@@ -149,13 +149,15 @@ public RealPointValuePair optimize(int maxEval, final FUNC f,
 
         // Multi-start loop.
         for (int i = 0; i < starts; ++i) {
+            // CHECKSTYLE: stop IllegalCatch
             try {
                 optima[i] = optimizer.optimize(maxEval - totalEvaluations, f, goal,
                                                i == 0 ? startPoint : generator.nextVector());
             } catch (RuntimeException mue) {
                 lastException = mue;
                 optima[i] = null;
             }
+            // CHECKSTYLE: resume IllegalCatch
 
             totalEvaluations += optimizer.getEvaluations();
         }

src/main/java/org/apache/commons/math/optimization/BaseMultiStartMultivariateVectorialOptimizer.java

@@ -151,6 +151,7 @@ public VectorialPointValuePair optimize(int maxEval, final FUNC f,
         // Multi-start loop.
         for (int i = 0; i < starts; ++i) {
 
+            // CHECKSTYLE: stop IllegalCatch
             try {
                 optima[i] = optimizer.optimize(maxEval - totalEvaluations, f, target, weights,
                                                i == 0 ? startPoint : generator.nextVector());
@@ -160,6 +161,7 @@ public VectorialPointValuePair optimize(int maxEval, final FUNC f,
                 lastException = mue;
                 optima[i] = null;
             }
+            // CHECKSTYLE: resume IllegalCatch
 
             totalEvaluations += optimizer.getEvaluations();
         }

src/main/java/org/apache/commons/math/optimization/univariate/MultiStartUnivariateRealOptimizer.java

@@ -161,13 +161,15 @@ public UnivariateRealPointValuePair optimize(int maxEval, final FUNC f,
 
         // Multi-start loop.
         for (int i = 0; i < starts; ++i) {
+            // CHECKSTYLE: stop IllegalCatch
             try {
                 final double s = (i == 0) ? startValue : min + generator.nextDouble() * (max - min);
                 optima[i] = optimizer.optimize(maxEval - totalEvaluations, f, goal, min, max, s);
             } catch (RuntimeException mue) {
                 lastException = mue;
                 optima[i] = null;
             }
+            // CHECKSTYLE: resume IllegalCatch
 
             totalEvaluations += optimizer.getEvaluations();
         }