SimpleRegression.java
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org.apache.commons.math.stat.regression |
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Commons Math |
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These are the metrics that contribute to the Enerjy Score for this file, ranked by impact. So the metrics listed at the top influence the score to a greater extent that the metrics listed at the bottom.
| Metric | Description | |
|---|---|---|
| DOC_COMMENT | Number of javadoc comment lines |  |
| COMMENTS | Comment lines | |
| DECL_COMMENTS | Comments in declarations | |
| JAVA0034 | JAVA0034 Missing braces in if statement | |
| JAVA0082 | JAVA0082 Unnecessary widening cast | |
| SIZE | Size of the file in bytes | |
| LINES | Number of lines in the source file | |
| JAVA0117 | JAVA0117 Missing javadoc: method 'method' | |
| PROGRAM_VOLUME | Halstead program volume | |
| JAVA0136 | JAVA0136 N methods defined in class (maximum: M) | |
| EXEC_COMMENTS | Comments in executable code | |
| JAVA0126 | JAVA0126 Method declares unchecked exception in throws | |
| JAVA0110 | JAVA0110 Incorrect javadoc: no @return tag | |
| LINE_COMMENT | Number of line comments | |
| JAVA0100 | JAVA0100 Class contains N non-final fields (maximum: M) | |
| LOOPS | Number of loops | |
| JAVA0108 | JAVA0108 Incorrect javadoc: no @param tag for 'parameter' | |
| ELOC | Effective lines of code | |
| UNIQUE_OPERATORS | Number of unique operators | |
| WHITESPACE | Number of whitespace lines | |
| OPERANDS | Number of operands | |
| CYCLOMATIC | Cyclomatic complexity | |
| LOC | Lines of code | |
| PARAMS | Number of formal parameter declarations | |
| EXITS | Procedure exits | |
| JAVA0270 | JAVA0270 Use Java 5.0 enhanced for loop construct to iterate over all elements in an array | |
| LOGICAL_LINES | Number of statements | |
| PROGRAM_LENGTH | Halstead program length | |
| JAVA0145 | JAVA0145 Tab character used in source file | |
| UNIQUE_OPERANDS | Number of unique operands | |
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.math.stat.regression;
import java.io.Serializable;
import org.apache.commons.math.MathException;
import org.apache.commons.math.distribution.TDistribution;
import org.apache.commons.math.distribution.TDistributionImpl;
/**
* Estimates an ordinary least squares regression model
* with one independent variable.
* <p>
* <code> y = intercept + slope * x </code></p>
* <p>
* Standard errors for <code>intercept</code> and <code>slope</code> are
* available as well as ANOVA, r-square and Pearson's r statistics.</p>
* <p>
* Observations (x,y pairs) can be added to the model one at a time or they
* can be provided in a 2-dimensional array. The observations are not stored
* in memory, so there is no limit to the number of observations that can be
* added to the model.</p>
* <p>
* <strong>Usage Notes</strong>: <ul>
* <li> When there are fewer than two observations in the model, or when
* there is no variation in the x values (i.e. all x values are the same)
* all statistics return <code>NaN</code>. At least two observations with
* different x coordinates are requred to estimate a bivariate regression
* model.
* </li>
* <li> getters for the statistics always compute values based on the current
* set of observations -- i.e., you can get statistics, then add more data
* and get updated statistics without using a new instance. There is no
* "compute" method that updates all statistics. Each of the getters performs
* the necessary computations to return the requested statistic.</li>
* </ul></p>
*
* @version $Revision: 617953 $ $Date: 2008-02-03 00:54:00 -0500 (Sun, 03 Feb 2008) $
*/
public class SimpleRegression implements Serializable {
/** Serializable version identifier */
private static final long serialVersionUID = -3004689053607543335L;
/** the distribution used to compute inference statistics. */
private TDistribution distribution;
/** sum of x values */
private double sumX = 0d;
/** total variation in x (sum of squared deviations from xbar) */
private double sumXX = 0d;
/** sum of y values */
private double sumY = 0d;
/** total variation in y (sum of squared deviations from ybar) */
private double sumYY = 0d;
/** sum of products */
private double sumXY = 0d;
/** number of observations */
private long n = 0;
/** mean of accumulated x values, used in updating formulas */
private double xbar = 0;
/** mean of accumulated y values, used in updating formulas */
private double ybar = 0;
// ---------------------Public methods--------------------------------------
/**
* Create an empty SimpleRegression instance
*/
public SimpleRegression() {
this(new TDistributionImpl(1.0));
}
/**
* Create an empty SimpleRegression using the given distribution object to
* compute inference statistics.
* @param t the distribution used to compute inference statistics.
* @since 1.2
*/
public SimpleRegression(TDistribution t) {
super();
setDistribution(t);
}
/**
* Adds the observation (x,y) to the regression data set.
* <p>
* Uses updating formulas for means and sums of squares defined in
* "Algorithms for Computing the Sample Variance: Analysis and
* Recommendations", Chan, T.F., Golub, G.H., and LeVeque, R.J.
* 1983, American Statistician, vol. 37, pp. 242-247, referenced in
* Weisberg, S. "Applied Linear Regression". 2nd Ed. 1985.</p>
*
*
* @param x independent variable value
* @param y dependent variable value
*/
public void addData(double x, double y) {
if (n == 0) {
xbar = x;
ybar = y;
} else {
double dx = x - xbar;
double dy = y - ybar;
sumXX += dx * dx * (double) n / (double) (n + 1.0);
sumYY += dy * dy * (double) n / (double) (n + 1.0);
sumXY += dx * dy * (double) n / (double) (n + 1.0);
xbar += dx / (double) (n + 1.0);
ybar += dy / (double) (n + 1.0);
}
sumX += x;
sumY += y;
n++;
if (n > 2) {
distribution.setDegreesOfFreedom(n - 2);
}
}
/**
* Adds the observations represented by the elements in
* <code>data</code>.
* <p>
* <code>(data[0][0],data[0][1])</code> will be the first observation, then
* <code>(data[1][0],data[1][1])</code>, etc.</p>
* <p>
* This method does not replace data that has already been added. The
* observations represented by <code>data</code> are added to the existing
* dataset.</p>
* <p>
* To replace all data, use <code>clear()</code> before adding the new
* data.</p>
*
* @param data array of observations to be added
*/
public void addData(double[][] data) {
for (int i = 0; i < data.length; i++) {
addData(data[i][0], data[i][1]);
}
}
/**
* Clears all data from the model.
*/
public void clear() {
sumX = 0d;
sumXX = 0d;
sumY = 0d;
sumYY = 0d;
sumXY = 0d;
n = 0;
}
/**
* Returns the number of observations that have been added to the model.
*
* @return n number of observations that have been added.
*/
public long getN() {
return n;
}
/**
* Returns the "predicted" <code>y</code> value associated with the
* supplied <code>x</code> value, based on the data that has been
* added to the model when this method is activated.
* <p>
* <code> predict(x) = intercept + slope * x </code></p>
* <p>
* <strong>Preconditions</strong>: <ul>
* <li>At least two observations (with at least two different x values)
* must have been added before invoking this method. If this method is
* invoked before a model can be estimated, <code>Double,NaN</code> is
* returned.
* </li></ul></p>
*
* @param x input <code>x</code> value
* @return predicted <code>y</code> value
*/
public double predict(double x) {
double b1 = getSlope();
return getIntercept(b1) + b1 * x;
}
/**
* Returns the intercept of the estimated regression line.
* <p>
* The least squares estimate of the intercept is computed using the
* <a href="http://www.xycoon.com/estimation4.htm">normal equations</a>.
* The intercept is sometimes denoted b0.</p>
* <p>
* <strong>Preconditions</strong>: <ul>
* <li>At least two observations (with at least two different x values)
* must have been added before invoking this method. If this method is
* invoked before a model can be estimated, <code>Double,NaN</code> is
* returned.
* </li></ul></p>
*
* @return the intercept of the regression line
*/
public double getIntercept() {
return getIntercept(getSlope());
}
/**
* Returns the slope of the estimated regression line.
* <p>
* The least squares estimate of the slope is computed using the
* <a href="http://www.xycoon.com/estimation4.htm">normal equations</a>.
* The slope is sometimes denoted b1.</p>
* <p>
* <strong>Preconditions</strong>: <ul>
* <li>At least two observations (with at least two different x values)
* must have been added before invoking this method. If this method is
* invoked before a model can be estimated, <code>Double.NaN</code> is
* returned.
* </li></ul></p>
*
* @return the slope of the regression line
*/
public double getSlope() {
if (n < 2) {
return Double.NaN; //not enough data
}
if (Math.abs(sumXX) < 10 * Double.MIN_VALUE) {
return Double.NaN; //not enough variation in x
}
return sumXY / sumXX;
}
/**
* Returns the <a href="http://www.xycoon.com/SumOfSquares.htm">
* sum of squared errors</a> (SSE) associated with the regression
* model.
* <p>
* The sum is computed using the computational formula</p>
* <p>
* <code>SSE = SYY - (SXY * SXY / SXX)</code></p>
* <p>
* where <code>SYY</code> is the sum of the squared deviations of the y
* values about their mean, <code>SXX</code> is similarly defined and
* <code>SXY</code> is the sum of the products of x and y mean deviations.
* </p><p>
* The sums are accumulated using the updating algorithm referenced in
* {@link #addData}.</p>
* <p>
* The return value is constrained to be non-negative - i.e., if due to
* rounding errors the computational formula returns a negative result,
* 0 is returned.</p>
* <p>
* <strong>Preconditions</strong>: <ul>
* <li>At least two observations (with at least two different x values)
* must have been added before invoking this method. If this method is
* invoked before a model can be estimated, <code>Double,NaN</code> is
* returned.
* </li></ul></p>
*
* @return sum of squared errors associated with the regression model
*/
public double getSumSquaredErrors() {
return Math.max(0d, sumYY - sumXY * sumXY / sumXX);
}
/**
* Returns the sum of squared deviations of the y values about their mean.
* <p>
* This is defined as SSTO
* <a href="http://www.xycoon.com/SumOfSquares.htm">here</a>.</p>
* <p>
* If <code>n < 2</code>, this returns <code>Double.NaN</code>.</p>
*
* @return sum of squared deviations of y values
*/
public double getTotalSumSquares() {
if (n < 2) {
return Double.NaN;
}
return sumYY;
}
/**
* Returns the sum of squared deviations of the predicted y values about
* their mean (which equals the mean of y).
* <p>
* This is usually abbreviated SSR or SSM. It is defined as SSM
* <a href="http://www.xycoon.com/SumOfSquares.htm">here</a></p>
* <p>
* <strong>Preconditions</strong>: <ul>
* <li>At least two observations (with at least two different x values)
* must have been added before invoking this method. If this method is
* invoked before a model can be estimated, <code>Double.NaN</code> is
* returned.
* </li></ul></p>
*
* @return sum of squared deviations of predicted y values
*/
public double getRegressionSumSquares() {
return getRegressionSumSquares(getSlope());
}
/**
* Returns the sum of squared errors divided by the degrees of freedom,
* usually abbreviated MSE.
* <p>
* If there are fewer than <strong>three</strong> data pairs in the model,
* or if there is no variation in <code>x</code>, this returns
* <code>Double.NaN</code>.</p>
*
* @return sum of squared deviations of y values
*/
public double getMeanSquareError() {
if (n < 3) {
return Double.NaN;
}
return getSumSquaredErrors() / (double) (n - 2);
}
/**
* Returns <a href="http://mathworld.wolfram.com/CorrelationCoefficient.html">
* Pearson's product moment correlation coefficient</a>,
* usually denoted r.
* <p>
* <strong>Preconditions</strong>: <ul>
* <li>At least two observations (with at least two different x values)
* must have been added before invoking this method. If this method is
* invoked before a model can be estimated, <code>Double,NaN</code> is
* returned.
* </li></ul></p>
*
* @return Pearson's r
*/
public double getR() {
double b1 = getSlope();
double result = Math.sqrt(getRSquare());
if (b1 < 0) {
result = -result;
}
return result;
}
/**
* Returns the <a href="http://www.xycoon.com/coefficient1.htm">
* coefficient of determination</a>,
* usually denoted r-square.
* <p>
* <strong>Preconditions</strong>: <ul>
* <li>At least two observations (with at least two different x values)
* must have been added before invoking this method. If this method is
* invoked before a model can be estimated, <code>Double,NaN</code> is
* returned.
* </li></ul></p>
*
* @return r-square
*/
public double getRSquare() {
double ssto = getTotalSumSquares();
return (ssto - getSumSquaredErrors()) / ssto;
}
/**
* Returns the <a href="http://www.xycoon.com/standarderrorb0.htm">
* standard error of the intercept estimate</a>,
* usually denoted s(b0).
* <p>
* If there are fewer that <strong>three</strong> observations in the
* model, or if there is no variation in x, this returns
* <code>Double.NaN</code>.</p>
*
* @return standard error associated with intercept estimate
*/
public double getInterceptStdErr() {
return Math.sqrt(
getMeanSquareError() * ((1d / (double) n) + (xbar * xbar) / sumXX));
}
/**
* Returns the <a href="http://www.xycoon.com/standerrorb(1).htm">standard
* error of the slope estimate</a>,
* usually denoted s(b1).
* <p>
* If there are fewer that <strong>three</strong> data pairs in the model,
* or if there is no variation in x, this returns <code>Double.NaN</code>.
* </p>
*
* @return standard error associated with slope estimate
*/
public double getSlopeStdErr() {
return Math.sqrt(getMeanSquareError() / sumXX);
}
/**
* Returns the half-width of a 95% confidence interval for the slope
* estimate.
* <p>
* The 95% confidence interval is</p>
* <p>
* <code>(getSlope() - getSlopeConfidenceInterval(),
* getSlope() + getSlopeConfidenceInterval())</code></p>
* <p>
* If there are fewer that <strong>three</strong> observations in the
* model, or if there is no variation in x, this returns
* <code>Double.NaN</code>.</p>
* <p>
* <strong>Usage Note</strong>:<br>
* The validity of this statistic depends on the assumption that the
* observations included in the model are drawn from a
* <a href="http://mathworld.wolfram.com/BivariateNormalDistribution.html">
* Bivariate Normal Distribution</a>.</p>
*
* @return half-width of 95% confidence interval for the slope estimate
* @throws MathException if the confidence interval can not be computed.
*/
public double getSlopeConfidenceInterval() throws MathException {
return getSlopeConfidenceInterval(0.05d);
}
/**
* Returns the half-width of a (100-100*alpha)% confidence interval for
* the slope estimate.
* <p>
* The (100-100*alpha)% confidence interval is </p>
* <p>
* <code>(getSlope() - getSlopeConfidenceInterval(),
* getSlope() + getSlopeConfidenceInterval())</code></p>
* <p>
* To request, for example, a 99% confidence interval, use
* <code>alpha = .01</code></p>
* <p>
* <strong>Usage Note</strong>:<br>
* The validity of this statistic depends on the assumption that the
* observations included in the model are drawn from a
* <a href="http://mathworld.wolfram.com/BivariateNormalDistribution.html">
* Bivariate Normal Distribution</a>.</p>
* <p>
* <strong> Preconditions:</strong><ul>
* <li>If there are fewer that <strong>three</strong> observations in the
* model, or if there is no variation in x, this returns
* <code>Double.NaN</code>.
* </li>
* <li><code>(0 < alpha < 1)</code>; otherwise an
* <code>IllegalArgumentException</code> is thrown.
* </li></ul></p>
*
* @param alpha the desired significance level
* @return half-width of 95% confidence interval for the slope estimate
* @throws MathException if the confidence interval can not be computed.
*/
public double getSlopeConfidenceInterval(double alpha)
throws MathException {
if (alpha >= 1 || alpha <= 0) {
throw new IllegalArgumentException();
}
return getSlopeStdErr() *
distribution.inverseCumulativeProbability(1d - alpha / 2d);
}
/**
* Returns the significance level of the slope (equiv) correlation.
* <p>
* Specifically, the returned value is the smallest <code>alpha</code>
* such that the slope confidence interval with significance level
* equal to <code>alpha</code> does not include <code>0</code>.
* On regression output, this is often denoted <code>Prob(|t| > 0)</code>
* </p><p>
* <strong>Usage Note</strong>:<br>
* The validity of this statistic depends on the assumption that the
* observations included in the model are drawn from a
* <a href="http://mathworld.wolfram.com/BivariateNormalDistribution.html">
* Bivariate Normal Distribution</a>.</p>
* <p>
* If there are fewer that <strong>three</strong> observations in the
* model, or if there is no variation in x, this returns
* <code>Double.NaN</code>.</p>
*
* @return significance level for slope/correlation
* @throws MathException if the significance level can not be computed.
*/
public double getSignificance() throws MathException {
return 2d * (1.0 - distribution.cumulativeProbability(
Math.abs(getSlope()) / getSlopeStdErr()));
}
// ---------------------Private methods-----------------------------------
/**
* Returns the intercept of the estimated regression line, given the slope.
* <p>
* Will return <code>NaN</code> if slope is <code>NaN</code>.</p>
*
* @param slope current slope
* @return the intercept of the regression line
*/
private double getIntercept(double slope) {
return (sumY - slope * sumX) / ((double) n);
}
/**
* Computes SSR from b1.
*
* @param slope regression slope estimate
* @return sum of squared deviations of predicted y values
*/
private double getRegressionSumSquares(double slope) {
return slope * slope * sumXX;
}
/**
* Modify the distribution used to compute inference statistics.
* @param value the new distribution
* @since 1.2
*/
public void setDistribution(TDistribution value) {
distribution = value;
// modify degrees of freedom
if (n > 2) {
distribution.setDegreesOfFreedom(n - 2);
}
}
}
The table below shows all metrics for SimpleRegression.java.
| Metric | Value | Description | |
|---|---|---|---|
| BLOCKS | 34.00 | Number of blocks | |
| BLOCK_COMMENT | 16.00 | Number of block comment lines | |
| COMMENTS | 362.00 | Comment lines | |
| COMMENT_DENSITY | 3.42 | Comment density | |
| COMPARISONS | 21.00 | Number of comparison operators | |
| CYCLOMATIC | 34.00 | Cyclomatic complexity | |
| DECL_COMMENTS | 37.00 | Comments in declarations | |
| DOC_COMMENT | 343.00 | Number of javadoc comment lines | |
| ELOC | 106.00 | Effective lines of code | |
| EXEC_COMMENTS | 1.00 | Comments in executable code | |
| EXITS | 17.00 | Procedure exits | |
| FUNCTIONS | 23.00 | Number of function declarations | |
| HALSTEAD_DIFFICULTY | 67.75 | Halstead difficulty | |
| HALSTEAD_EFFORT | 0.00 | Halstead effort | |
| INTERFACE_COMPLEXITY | 40.00 | Interface complexity | |
| JAVA0001 | 0.00 | JAVA0001 Package name does not contain only lower case letters | |
| JAVA0002 | 0.00 | JAVA0002 Package name does not begin with a top level domain name or country code | |
| JAVA0003 | 0.00 | JAVA0003 Minimize use of on-demand (.*) imports | |
| JAVA0004 | 0.00 | JAVA0004 Unnecessary import from java.lang | |
| JAVA0005 | 0.00 | JAVA0005 Imports not in specified order | |
| JAVA0006 | 0.00 | JAVA0006 Empty finally block | |
| JAVA0007 | 0.00 | JAVA0007 Should not declare public field | |
| JAVA0008 | 0.00 | JAVA0008 Empty catch block | |
| JAVA0009 | 0.00 | JAVA0009 Protected member in final class | |
| JAVA0010 | 0.00 | JAVA0010 Non-instantiable class does not contain a non-private static member | |
| JAVA0011 | 0.00 | JAVA0011 Abstract class does not contain an abstract method | |
| JAVA0012 | 0.00 | JAVA0012 Non-constructor method with same name as declaring class | |
| JAVA0013 | 0.00 | JAVA0013 Non-blank final field is not static | |
| JAVA0014 | 0.00 | JAVA0014 Class with only static members has non-private constructor | |
| JAVA0015 | 0.00 | JAVA0015 Package class contains public nested type | |
| JAVA0016 | 0.00 | JAVA0016 Abstract class contains public constructor | |
| JAVA0017 | 0.00 | JAVA0017 Class name does not have required form | |
| JAVA0018 | 0.00 | JAVA0018 Method name does not have required form | |
| JAVA0019 | 0.00 | JAVA0019 Interface name does not have required form | |
| JAVA0020 | 0.00 | JAVA0020 Field name does not have required form | |
| JAVA0021 | 0.00 | JAVA0021 Interface method name does not have required form | |
| JAVA0022 | 0.00 | JAVA0022 Static final field name does not have required form | |
| JAVA0023 | 0.00 | JAVA0023 Empty finalize method | |
| JAVA0024 | 0.00 | JAVA0024 Empty class | |
| JAVA0025 | 0.00 | JAVA0025 Method override is empty | |
| JAVA0026 | 0.00 | JAVA0026 Finalize method with parameters | |
| JAVA0029 | 0.00 | JAVA0029 Private method not used | |
| JAVA0030 | 0.00 | JAVA0030 Private field not used | |
| JAVA0031 | 0.00 | JAVA0031 Case statement not properly closed | |
| JAVA0032 | 0.00 | JAVA0032 Switch statement missing default | |
| JAVA0033 | 0.00 | JAVA0033 default: not last case in switch statement | |
| JAVA0034 | 0.00 | JAVA0034 Missing braces in if statement | |
| JAVA0035 | 0.00 | JAVA0035 Missing braces in for statement | |
| JAVA0036 | 0.00 | JAVA0036 Missing braces in while statement | |
| JAVA0038 | 0.00 | JAVA0038 Non-case label in switch statement | |
| JAVA0039 | 0.00 | JAVA0039 Break statement with label | |
| JAVA0040 | 0.00 | JAVA0040 Switch statement contains N cases (maximum: M) | |
| JAVA0041 | 0.00 | JAVA0041 Nested synchronized block | |
| JAVA0042 | 0.00 | JAVA0042 Empty synchronized statement | |
| JAVA0043 | 0.00 | JAVA0043 Inner class does not use outer class | |
| JAVA0044 | 0.00 | JAVA0044 Serializable class with no instance variables | |
| JAVA0045 | 0.00 | JAVA0045 Serializable class with only transient fields | |
| JAVA0046 | 0.00 | JAVA0046 Name of class not derived from Exception ends with 'Exception' | |
| JAVA0047 | 0.00 | JAVA0047 Serializable class derives from invalid base class | |
| JAVA0048 | 0.00 | JAVA0048 Name of class derived from Exception does not end with 'Exception' | |
| JAVA0049 | 0.00 | JAVA0049 Nested block at depth N (maximum: M) | |
| JAVA0050 | 0.00 | JAVA0050 Class derives from java.lang.Error | |
| JAVA0051 | 0.00 | JAVA0051 Class derives from java.lang.RuntimeException | |
| JAVA0052 | 0.00 | JAVA0052 Class derives from java.lang.Throwable | |
| JAVA0053 | 0.00 | JAVA0053 Unused label | |
| JAVA0054 | 0.00 | JAVA0054 Inheritance depth N exceeds maximum M | |
| JAVA0055 | 0.00 | JAVA0055 Class should be interface | |
| JAVA0056 | 0.00 | JAVA0056 Unnecessary abstract modifier for interface or annotation | |
| JAVA0057 | 0.00 | JAVA0057 Unnecessary default constructor | |
| JAVA0058 | 1.00 | JAVA0058 Constructor calls super() | |
| JAVA0059 | 0.00 | JAVA0059 Method override only calls super() | |
| JAVA0061 | 0.00 | JAVA0061 Inaccessible member in anonymous class | |
| JAVA0062 | 0.00 | JAVA0062 Public class missing public member or protected constructor | |
| JAVA0063 | 0.00 | JAVA0063 Identifier name should not contain '$' | |
| JAVA0064 | 0.00 | JAVA0064 N variations of identifier name (maximum: M) | |
| JAVA0065 | 0.00 | JAVA0065 Unnecessary final modifier for method in final class | |
| JAVA0066 | 0.00 | JAVA0066 Unnecessary modifier for interface nested type | |
| JAVA0067 | 0.00 | JAVA0067 Array descriptor on identifier name | |
| JAVA0068 | 0.00 | JAVA0068 Modifiers not declared in recommended order | |
| JAVA0071 | 0.00 | JAVA0071 Strings compared with == | |
| JAVA0073 | 0.00 | JAVA0073 Integer division in floating-point context | |
| JAVA0074 | 0.00 | JAVA0074 Use of Object.notify() | |
| JAVA0075 | 0.00 | JAVA0075 Method parameter hides field | |
| JAVA0076 | 0.00 | JAVA0076 Use of magic number | |
| JAVA0077 | 0.00 | JAVA0077 Private field not used in declaring class | |
| JAVA0078 | 0.00 | JAVA0078 Floating point values compared with == | |
| JAVA0079 | 0.00 | JAVA0079 Use of instance to reference static member | |
| JAVA0080 | 0.00 | JAVA0080 Import declaration not used | |
| JAVA0081 | 0.00 | JAVA0081 Boolean literal in comparison | |
| JAVA0082 | 5.00 | JAVA0082 Unnecessary widening cast | |
| JAVA0083 | 0.00 | JAVA0083 Unnecessary instanceof test | |
| JAVA0084 | 0.00 | JAVA0084 Should use compound assignment operator | |
| JAVA0085 | 0.00 | JAVA0085 Use of sun.* class | |
| JAVA0087 | 0.00 | JAVA0087 Use of Thread.sleep() | |
| JAVA0089 | 0.00 | JAVA0089 Use of restricted package | |
| JAVA0092 | 0.00 | JAVA0092 Use of restricted type | |
| JAVA0093 | 0.00 | JAVA0093 Redundant assignment | |
| JAVA0094 | 0.00 | JAVA0094 Field hides a superclass field | |
| JAVA0095 | 0.00 | JAVA0095 Uninitialized private field | |
| JAVA0096 | 0.00 | JAVA0096 Field in nested class hides outer field | |
| JAVA0098 | 0.00 | JAVA0098 Minimize use of implicit field initializers | |
| JAVA0100 | 1.00 | JAVA0100 Class contains N non-final fields (maximum: M) | |
| JAVA0101 | 0.00 | JAVA0101 Unnecessary modifier for field in interface | |
| JAVA0102 | 0.00 | JAVA0102 Last statement in finalize() not super.finalize() | |
| JAVA0103 | 0.00 | JAVA0103 Explicit call to finalize() | |
| JAVA0104 | 0.00 | JAVA0104 finalize() only calls super.finalize() | |
| JAVA0105 | 0.00 | JAVA0105 Duplicate import declaration | |
| JAVA0106 | 0.00 | JAVA0106 Unnecessary import from current package | |
| JAVA0108 | 0.00 | JAVA0108 Incorrect javadoc: no @param tag for 'parameter' | |
| JAVA0109 | 0.00 | JAVA0109 Incorrect javadoc: no parameter 'parameter' | |
| JAVA0110 | 0.00 | JAVA0110 Incorrect javadoc: no @return tag | |
| JAVA0111 | 0.00 | JAVA0111 Incorrect javadoc: @return tag for void method | |
| JAVA0112 | 0.00 | JAVA0112 Incorrect javadoc: no exception 'exception' in throws | |
| JAVA0113 | 1.00 | JAVA0113 Incorrect javadoc: no @author tag | |
| JAVA0114 | 0.00 | JAVA0114 Incorrect javadoc: no @version tag | |
| JAVA0115 | 0.00 | JAVA0115 Incorrect javadoc: no @throws or @exception tag for 'exception' | |
| JAVA0116 | 0.00 | JAVA0116 Missing javadoc: field 'field' | |
| JAVA0117 | 0.00 | JAVA0117 Missing javadoc: method 'method' | |
| JAVA0118 | 0.00 | JAVA0118 Missing javadoc: type 'type' | |
| JAVA0119 | 0.00 | JAVA0119 Control variable changed within body of for loop | |
| JAVA0123 | 0.00 | JAVA0123 Use all three components of for loop | |
| JAVA0125 | 0.00 | JAVA0125 Continue statement with label | |
| JAVA0126 | 0.00 | JAVA0126 Method declares unchecked exception in throws | |
| JAVA0128 | 0.00 | JAVA0128 Public constructor in non-public class | |
| JAVA0130 | 0.00 | JAVA0130 Non-static method does not use instance fields | |
| JAVA0131 | 0.00 | JAVA0131 Compatible method does not override base | |
| JAVA0132 | 0.00 | JAVA0132 Method overload with compatible signature | |
| JAVA0133 | 0.00 | JAVA0133 Non-synchronized method overrides synchronized method | |
| JAVA0135 | 0.00 | JAVA0135 Only one of Object.equals and Object.hashCode defined: missing 'method' | |
| JAVA0136 | 1.00 | JAVA0136 N methods defined in class (maximum: M) | |
| JAVA0137 | 0.00 | JAVA0137 Non-abstract class missing constructor | |
| JAVA0138 | 0.00 | JAVA0138 N parameters defined for method (maximum: M) | |
| JAVA0139 | 0.00 | JAVA0139 Definition of main other than public static void main(java.lang.String[]) | |
| JAVA0141 | 0.00 | JAVA0141 Unnecessary modifier for method in interface | |
| JAVA0143 | 0.00 | JAVA0143 Synchronized method | |
| JAVA0144 | 0.00 | JAVA0144 Line exceeds maximum M characters | |
| JAVA0145 | 0.00 | JAVA0145 Tab character used in source file | |
| JAVA0150 | 0.00 | JAVA0150 java.lang.Error (or subclass) thrown | |
| JAVA0153 | 0.00 | JAVA0153 Inefficient conversion of integer to string | |
| JAVA0159 | 0.00 | JAVA0159 Inefficient conversion of string to integer | |
| JAVA0160 | 0.00 | JAVA0160 Method does not throw specified exception | |
| JAVA0161 | 0.00 | JAVA0161 Conditional wait() not in loop | |
| JAVA0163 | 0.00 | JAVA0163 Empty statement | |
| JAVA0165 | 0.00 | JAVA0165 Conflicting return statement in finally block | |
| JAVA0166 | 0.00 | JAVA0166 Generic exception caught | |
| JAVA0167 | 0.00 | JAVA0167 ThreadDeath not rethrown | |
| JAVA0169 | 0.00 | JAVA0169 Unnecessary catch block: exception 'exception' | |
| JAVA0170 | 0.00 | JAVA0170 Caught exception not derived from java.lang.Exception | |
| JAVA0171 | 0.00 | JAVA0171 Unused local variable | |
| JAVA0173 | 0.00 | JAVA0173 Unused method parameter | |
| JAVA0174 | 0.00 | JAVA0174 Assigned local variable never used | |
| JAVA0175 | 0.00 | JAVA0175 Successive assignment to variable | |
| JAVA0176 | 0.00 | JAVA0176 Local variable name does not have required form | |
| JAVA0177 | 0.00 | JAVA0177 Variable declaration missing initializer | |
| JAVA0179 | 0.00 | JAVA0179 Local variable hides visible field | |
| JAVA0233 | 0.00 | JAVA0233 Definition of serialVersionUID other than 'private static final long serialVersionUID' | |
| JAVA0234 | 0.00 | JAVA0234 Class is Serializable but does not define serialVersionUID | |
| JAVA0235 | 0.00 | JAVA0235 Class defines serialVersionUID but does not implement Serializable | |
| JAVA0236 | 0.00 | JAVA0236 Attempt to clone an object which does not implement Cloneable | |
| JAVA0237 | 0.00 | JAVA0237 Class implements Cloneable but does not have public clone method | |
| JAVA0238 | 0.00 | JAVA0238 Clone method does not call super.clone() | |
| JAVA0239 | 0.00 | JAVA0239 Class declares 'readObject' or 'writeObject' but does not implement Serializable | |
| JAVA0240 | 0.00 | JAVA0240 Serializable class which declares readObject or writeObject but not both | |
| JAVA0241 | 0.00 | JAVA0241 'readObject' or 'writeObject' should be declared private in Serializable class | |
| JAVA0242 | 0.00 | JAVA0242 Transient field in non-Serializable class | |
| JAVA0243 | 0.00 | JAVA0243 'readResolve' or 'writeReplace' should be declared private or protected | |
| JAVA0244 | 0.00 | JAVA0244 Field or method name in subclass differs only by case from inherited field or method | |
| JAVA0245 | 0.00 | JAVA0245 JUnit TestCase with non-trivial constructor | |
| JAVA0246 | 0.00 | JAVA0246 JUnit assertXXX statement missing message parameter | |
| JAVA0247 | 0.00 | JAVA0247 JUnit 'setUp()' and 'tearDown()' should call super method | |
| JAVA0248 | 0.00 | JAVA0248 JUnit method 'setUp' or 'tearDown' with incorrect signature | |
| JAVA0249 | 0.00 | JAVA0249 JUnit TestCase 'suite()' should be declared static | |
| JAVA0250 | 0.00 | JAVA0250 JUnit TestCase declares testXXX method with incorrect signature | |
| JAVA0251 | 0.00 | JAVA0251 Use '%n' for line breaks in printf/format for platform independence | |
| JAVA0252 | 0.00 | JAVA0252 'enum' is a Java 1.5 reserved word | |
| JAVA0253 | 0.00 | JAVA0253 Not all enum constants consumed in switch statement | |
| JAVA0254 | 0.00 | JAVA0254 Use enhanced for loop construct instead of Iterator | |
| JAVA0255 | 0.00 | JAVA0255 Result of method invocation not used | |
| JAVA0256 | 0.00 | JAVA0256 Assignment of external collection/array to field | |
| JAVA0257 | 0.00 | JAVA0257 Use of 'Constant Interface' anti-pattern | |
| JAVA0258 | 0.00 | JAVA0258 Implement Iterable for foreach compatibility | |
| JAVA0259 | 0.00 | JAVA0259 Return of collection/array field | |
| JAVA0260 | 0.00 | JAVA0260 Use 'enum' instead of Enumerated Type pattern | |
| JAVA0261 | 0.00 | JAVA0261 Use specialized Enum collection types | |
| JAVA0262 | 0.00 | JAVA0262 Use of char in integer context | |
| JAVA0263 | 0.00 | JAVA0263 Long literal ends with 'l' instead of 'L' | |
| JAVA0264 | 0.00 | JAVA0264 Integer math in long context - check for overflow | |
| JAVA0265 | 0.00 | JAVA0265 Use of Throwable.printStackTrace() | |
| JAVA0266 | 0.00 | JAVA0266 Use of System.out | |
| JAVA0267 | 0.00 | JAVA0267 Use of System.err | |
| JAVA0269 | 0.00 | JAVA0269 Contents of StringBuffer never used | |
| JAVA0270 | 1.00 | JAVA0270 Use Java 5.0 enhanced for loop construct to iterate over all elements in an array | |
| JAVA0271 | 0.00 | JAVA0271 Minimize use of on-demand (.*) static imports | |
| JAVA0272 | 0.00 | JAVA0272 Thread.run() called | |
| JAVA0273 | 0.00 | JAVA0273 Non-final derivative of Thread calls start() in constructor | |
| JAVA0274 | 0.00 | JAVA0274 Serializable class has a synchronized readObject() | |
| JAVA0275 | 0.00 | JAVA0275 Serializable class has a synchronized writeObject() and no other synchronized methods | |
| JAVA0276 | 0.00 | JAVA0276 Unnecessary use of String constructor | |
| JAVA0277 | 0.00 | JAVA0277 Iterator.next() implementation does not throw NoSuchElementException | |
| JAVA0278 | 0.00 | JAVA0278 Unnecessary use of Boolean constructor | |
| JAVA0279 | 0.00 | JAVA0279 Serialization method readObject or readObjectNoData calls an overridable method | |
| JAVA0280 | 0.00 | JAVA0280 IllegalMonitorStateException caught | |
| JAVA0281 | 0.00 | JAVA0281 Iterator.next() not called in loop | |
| JAVA0282 | 0.00 | JAVA0282 Call to Iterator.next() in loop which does not test Iterator.hasNext() | |
| JAVA0283 | 0.00 | JAVA0283 Control variable not updated in loop body | |
| JAVA0284 | 0.00 | JAVA0284 Explicit garbage collection | |
| JAVA0285 | 0.00 | JAVA0285 Dereference of potentially null variable | |
| JAVA0286 | 0.00 | JAVA0286 Dereference of null variable | |
| JAVA0287 | 0.00 | JAVA0287 Unnecessary null check | |
| JAVA0288 | 0.00 | JAVA0288 Inconsistent null check | |
| LINES | 542.00 | Number of lines in the source file | |
| LINE_COMMENT | 3.00 | Number of line comments | |
| LOC | 140.00 | Lines of code | |
| LOGICAL_LINES | 69.00 | Number of statements | |
| LOOPS | 1.00 | Number of loops | |
| NEST_DEPTH | 2.00 | Maximum nesting depth | |
| OPERANDS | 271.00 | Number of operands | |
| OPERATORS | 606.00 | Number of operators | |
| PARAMS | 9.00 | Number of formal parameter declarations | |
| PROGRAM_LENGTH | 877.00 | Halstead program length | |
| PROGRAM_VOCAB | 129.00 | Halstead program vocabulary | |
| PROGRAM_VOLUME | 0.00 | Halstead program volume | |
| RETURNS | 31.00 | Number of return points from functions | |
| SIZE | 19460.00 | Size of the file in bytes | |
| UNIQUE_OPERANDS | 86.00 | Number of unique operands | |
| UNIQUE_OPERATORS | 43.00 | Number of unique operators | |
| WHITESPACE | 40.00 | Number of whitespace lines | |