replaced a catch for Exception by a catch for NumberFormatException

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@810243 13f79535-47bb-0310-9956-ffa450edef68

src/main/java/org/apache/commons/math/util/DefaultTransformer.java

@@ -53,7 +53,7 @@ public class DefaultTransformer implements NumberTransformer, Serializable {
             
         try {
             return Double.valueOf(o.toString()).doubleValue();
-        } catch (Exception e) {
+        } catch (NumberFormatException e) {
             throw new MathException(e,
                                     "Conversion Exception in Transformation: {0}", e.getMessage());
         }