Fix PMD findings from Commons Parent 102

commons-statistics-inference/src/main/java/org/apache/commons/statistics/inference/KolmogorovSmirnovDistribution.java

@@ -547,11 +547,6 @@ static double pelzGood(double x, int n) {
             // This is the form for K0.
             // Compute all together over odd integers and divide factors
             // of (k + 1/2)^b by 2^b.
-            double k0 = 0;
-            double k1 = 0;
-            double k2 = 0;
-            double k3 = 0;
-
             final double rootN = Math.sqrt(n);
             final double z = x * rootN;
             final double z3 = z * z2;
@@ -579,6 +574,10 @@ static double pelzGood(double x, int n) {
             // 0 = k^2 - k + log(eps) * 2z^2 / pi^2
             // Solve using quadratic equation and eps = ulp(1.0): 4a ~ -288
             final int max = (int) Math.ceil((1 + Math.sqrt(1 - FOUR_A * z2 / PI2)) / 2);
+            double k0 = 0;
+            double k1 = 0;
+            double k2 = 0;
+            double k3 = 0;
             // Sum smallest terms first
             for (int k = max; k > 0; k--) {
                 final int j = 2 * k - 1;

commons-statistics-inference/src/main/java/org/apache/commons/statistics/inference/SquareMatrixSupport.java

@@ -153,8 +153,6 @@ public RealSquareMatrix power(int n) {
 
             // Working arrays
             final double[] col = new double[dim];
-            double[] b = new double[data.length];
-            double[] tmp;
 
             // Initialise result as A^1.
             final double[] a = data;
@@ -168,6 +166,8 @@ public RealSquareMatrix power(int n) {
             int bits = n << shift;
 
             // Process remaining bits below highest set bit.
+            double[] b = new double[data.length];
+            double[] tmp;
             for (int i = 32 - shift; i != 0; i--, bits <<= 1) {
                 // Square the result
                 er = multiply(r, er, r, er, col, b);

src/conf/pmd/pmd-ruleset.xml

@@ -104,6 +104,14 @@
         value="./ancestor-or-self::MethodDeclaration[@Name='twoSampleTwoSidedPStabilizedInner']"/>
     </properties>
   </rule>
+  <rule ref="category/java/codestyle.xml/VariableDeclarationUsageDistance">
+    <properties>
+      <!-- Brent algorithm state must persist across iterations. -->
+      <property name="violationSuppressXPath"
+        value="./ancestor-or-self::MethodDeclaration[@Name='optimize'
+          and ancestor::ClassDeclaration[@SimpleName='BrentOptimizer']]"/>
+    </properties>
+  </rule>
   <rule ref="category/java/codestyle.xml/LinguisticNaming">
     <properties>
       <!-- Allow builder pattern for configuring statistics for fluent chaining -->