Remove redundant variable Initializer

src/main/java/org/apache/commons/math4/distribution/EmpiricalDistribution.java

@@ -117,7 +117,7 @@ public class EmpiricalDistribution extends AbstractRealDistribution
     private final List<SummaryStatistics> binStats;
 
     /** Sample statistics */
-    private SummaryStatistics sampleStats = null;
+    private SummaryStatistics sampleStats;
 
     /** Max loaded value */
     private double max = Double.NEGATIVE_INFINITY;
@@ -126,16 +126,16 @@ public class EmpiricalDistribution extends AbstractRealDistribution
     private double min = Double.POSITIVE_INFINITY;
 
     /** Grid size */
-    private double delta = 0d;
+    private double delta;
 
     /** number of bins */
     private final int binCount;
 
     /** is the distribution loaded? */
-    private boolean loaded = false;
+    private boolean loaded;
 
     /** upper bounds of subintervals in (0,1) "belonging" to the bins */
-    private double[] upperBounds = null;
+    private double[] upperBounds;
 
     /**
      * Creates a new EmpiricalDistribution with the default bin count.

src/main/java/org/apache/commons/math4/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java

@@ -71,7 +71,7 @@ public class MultivariateNormalMixtureExpectationMaximization {
     /**
      * The log likelihood of the data given the fitted model.
      */
-    private double logLikelihood = 0d;
+    private double logLikelihood;
 
     /**
      * Creates an object to fit a multivariate normal mixture model to data.

src/main/java/org/apache/commons/math4/genetics/FixedGenerationCount.java

@@ -29,7 +29,7 @@
  */
 public class FixedGenerationCount implements StoppingCondition {
     /** Number of generations that have passed */
-    private int numGenerations = 0;
+    private int numGenerations;
 
     /** Maximum number of generations (stopping criteria) */
     private final int maxGenerations;

src/main/java/org/apache/commons/math4/genetics/GeneticAlgorithm.java

@@ -53,7 +53,7 @@ public class GeneticAlgorithm {
     private final SelectionPolicy selectionPolicy;
 
     /** the number of generations evolved to reach {@link StoppingCondition} in the last run. */
-    private int generationsEvolved = 0;
+    private int generationsEvolved;
 
     /**
      * Create a new genetic algorithm.

src/main/java/org/apache/commons/math4/linear/RealVector.java

@@ -753,7 +753,7 @@ public Iterator<Entry> iterator() {
         return new Iterator<Entry>() {
 
             /** Current index. */
-            private int i = 0;
+            private int i;
 
             /** Current entry. */
             private Entry e = new Entry();

src/main/java/org/apache/commons/math4/ml/clustering/MiniBatchKMeansClusterer.java

@@ -254,7 +254,7 @@ private static class ImprovementEvaluator {
         /** Minimum value of {@link #ewaInertia} during iteration. */
         private double ewaInertiaMin = Double.POSITIVE_INFINITY;
         /** Number of iteration during which {@link #ewaInertia} did not improve. */
-        private int noImprovementTimes = 0;
+        private int noImprovementTimes;
 
         /**
          * @param batchSize Number of elements for each batch iteration.

src/main/java/org/apache/commons/math4/random/HaltonSequenceGenerator.java

@@ -71,7 +71,7 @@ public class HaltonSequenceGenerator implements RandomVectorGenerator {
     private final int dimension;
 
     /** The current index in the sequence. */
-    private int count = 0;
+    private int count;
 
     /** The base numbers for each component. */
     private final int[] base;

src/main/java/org/apache/commons/math4/random/SobolSequenceGenerator.java

@@ -74,7 +74,7 @@ public class SobolSequenceGenerator implements RandomVectorGenerator {
     private final int dimension;
 
     /** The current index in the sequence. */
-    private int count = 0;
+    private int count;
 
     /** The direction vector for each component. */
     private final long[][] direction;

src/main/java/org/apache/commons/math4/stat/descriptive/MultivariateSummaryStatistics.java

@@ -78,7 +78,7 @@ public class MultivariateSummaryStatistics
     private final int k;
 
     /** Count of values that have been added */
-    private long n = 0;
+    private long n;
 
     /** Sum statistic implementation - can be reset by setter. */
     private final StorelessUnivariateStatistic[] sumImpl;

src/main/java/org/apache/commons/math4/stat/descriptive/SummaryStatistics.java

@@ -63,7 +63,7 @@ public class SummaryStatistics implements StatisticalSummary, Serializable {
     private static final long serialVersionUID = -2021321786743555871L;
 
     /** count of values that have been added */
-    private long n = 0;
+    private long n;
 
     /** SecondMoment is used to compute the mean and variance */
     private SecondMoment secondMoment = new SecondMoment();

src/main/java/org/apache/commons/math4/stat/descriptive/moment/Skewness.java

@@ -51,7 +51,7 @@ public class Skewness extends AbstractStorelessUnivariateStatistic implements Se
     private static final long serialVersionUID = 20150412L;
 
     /** Third moment on which this statistic is based */
-    protected ThirdMoment moment = null;
+    protected ThirdMoment moment;
 
      /**
      * Determines whether or not this statistic can be incremented or cleared.

src/main/java/org/apache/commons/math4/stat/descriptive/moment/StandardDeviation.java

@@ -46,7 +46,7 @@ public class StandardDeviation extends AbstractStorelessUnivariateStatistic
     private static final long serialVersionUID = 20150412L;
 
     /** Wrapped Variance instance */
-    private Variance variance = null;
+    private Variance variance;
 
     /**
      * Constructs a StandardDeviation.  Sets the underlying {@link Variance}

src/main/java/org/apache/commons/math4/stat/descriptive/moment/Variance.java

@@ -72,7 +72,7 @@ public class Variance extends AbstractStorelessUnivariateStatistic implements Se
     private static final long serialVersionUID = 20150412L;
 
     /** SecondMoment is used in incremental calculation of Variance*/
-    protected SecondMoment moment = null;
+    protected SecondMoment moment;
 
     /**
      * Whether or not {@link #increment(double)} should increment

src/main/java/org/apache/commons/math4/stat/descriptive/rank/PSquarePercentile.java

@@ -99,7 +99,7 @@ public class PSquarePercentile extends AbstractStorelessUnivariateStatistic
      * Markers is the marker collection object which comes to effect
      * only after 5 values are inserted
      */
-    private PSquareMarkers markers = null;
+    private PSquareMarkers markers;
 
     /**
      * Computed p value (i,e percentile value of data set hither to received)

src/main/java/org/apache/commons/math4/stat/regression/AbstractMultipleLinearRegression.java

@@ -44,7 +44,7 @@ public abstract class AbstractMultipleLinearRegression implements
     private RealVector yVector;
 
     /** Whether or not the regression model includes an intercept.  True means no intercept. */
-    private boolean noIntercept = false;
+    private boolean noIntercept;
 
     /**
      * @return the X sample data.

src/main/java/org/apache/commons/math4/stat/regression/MillerUpdatingRegression.java

@@ -58,23 +58,23 @@ public class MillerUpdatingRegression implements UpdatingMultipleLinearRegressio
     /** scratch space for tolerance calc */
     private final double[] work_tolset;
     /** number of observations entered */
-    private long nobs = 0;
+    private long nobs;
     /** sum of squared errors of largest regression */
-    private double sserr = 0.0;
+    private double sserr;
     /** has rss been called? */
-    private boolean rss_set = false;
+    private boolean rss_set;
     /** has the tolerance setting method been called */
-    private boolean tol_set = false;
+    private boolean tol_set;
     /** flags for variables with linear dependency problems */
     private final boolean[] lindep;
     /** singular x values */
     private final double[] x_sing;
     /** workspace for singularity method */
     private final double[] work_sing;
     /** summation of Y variable */
-    private double sumy = 0.0;
+    private double sumy;
     /** summation of squared Y values */
-    private double sumsqy = 0.0;
+    private double sumsqy;
     /** boolean flag whether a regression constant is added */
     private final boolean hasIntercept;
     /** zero tolerance */

src/main/java/org/apache/commons/math4/stat/regression/OLSMultipleLinearRegression.java

@@ -54,7 +54,7 @@
 public class OLSMultipleLinearRegression extends AbstractMultipleLinearRegression {
 
     /** Cached QR decomposition of X matrix */
-    private QRDecomposition qr = null;
+    private QRDecomposition qr;
 
     /** Singularity threshold for QR decomposition */
     private final double threshold;

src/main/java/org/apache/commons/math4/stat/regression/SimpleRegression.java

@@ -66,28 +66,28 @@ public class SimpleRegression implements Serializable, UpdatingMultipleLinearReg
     private static final long serialVersionUID = -3004689053607543335L;
 
     /** sum of x values */
-    private double sumX = 0d;
+    private double sumX;
 
     /** total variation in x (sum of squared deviations from xbar) */
-    private double sumXX = 0d;
+    private double sumXX;
 
     /** sum of y values */
-    private double sumY = 0d;
+    private double sumY;
 
     /** total variation in y (sum of squared deviations from ybar) */
-    private double sumYY = 0d;
+    private double sumYY;
 
     /** sum of products */
-    private double sumXY = 0d;
+    private double sumXY;
 
     /** number of observations */
-    private long n = 0;
+    private long n;
 
     /** mean of accumulated x values, used in updating formulas */
-    private double xbar = 0;
+    private double xbar;
 
     /** mean of accumulated y values, used in updating formulas */
-    private double ybar = 0;
+    private double ybar;
 
     /** include an intercept or not */
     private final boolean hasIntercept;

src/main/java/org/apache/commons/math4/util/IntegerSequence.java

@@ -148,7 +148,7 @@ public void trigger(int max) throws MaxCountExceededException {
         /** Function called at counter exhaustion. */
         private final MaxCountExceededCallback maxCountCallback;
         /** Current count. */
-        private int count = 0;
+        private int count;
 
         /**
          * Defines a method to be called at counter exhaustion.

src/main/java/org/apache/commons/math4/util/ResizableDoubleArray.java

@@ -120,14 +120,14 @@ public class ResizableDoubleArray implements DoubleArray, Serializable {
      * The number of addressable elements in the array.  Note that this
      * has nothing to do with the length of the internal storage array.
      */
-    private int numElements = 0;
+    private int numElements;
 
     /**
      * The position of the first addressable element in the internal storage
      * array.  The addressable elements in the array are
      * {@code internalArray[startIndex],...,internalArray[startIndex + numElements - 1]}.
      */
-    private int startIndex = 0;
+    private int startIndex;
 
     /**
      * Specification of expansion algorithm.

src/main/java/org/apache/commons/math4/util/TransformerMap.java

@@ -38,12 +38,12 @@ public class TransformerMap implements NumberTransformer, Serializable {
     /**
      * A default Number Transformer for Numbers and numeric Strings.
      */
-    private NumberTransformer defaultTransformer = null;
+    private NumberTransformer defaultTransformer;
 
     /**
      * The internal Map.
      */
-    private Map<Class<?>, NumberTransformer> map = null;
+    private Map<Class<?>, NumberTransformer> map;
 
     /**
      * Build a map containing only the default transformer.