Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.math.simpleStats;

/**

 * A class to calculate some basic statistics

 * 

 * @author volaya

 * 

 */

public class SimpleStats {

   //private final ArrayList m_Values;

   private double m_dSum;

   private double m_dRMS;

   private double m_dMean;

   private double m_dVariance;

   private double m_dMax, m_dMin;

   private double m_dStdDev;

   //private boolean   m_bCalculated;

   private int    m_iCount;

   private double m_dM2;

   public SimpleStats() {

      //m_Values = new ArrayList();

      //m_bCalculated = false;

      m_iCount = 0;

      m_dMax = Double.NEGATIVE_INFINITY;

      m_dMin = Double.MAX_VALUE;

      m_dSum = 0;

      m_dRMS = 0;

      m_dM2 = 0;

   }

   public void addValue() {

      m_iCount++;

   }

   /**

    * adds a new value to the list of values

    * 

    * @param dValue

    *                the value

    */

   public void addValue(final double dValue) {

      m_iCount++;

      final double dDelta = dValue - m_dMean;

      m_dMean = m_dMean + dDelta / m_iCount;

      m_dM2 = m_dM2 + dDelta * (dValue - m_dMean);

      m_dVariance = m_dM2 / (m_iCount - 1);

      m_dSum += dValue;

      m_dRMS += dValue * dValue;

      m_dMax = Math.max(m_dMax, dValue);

      m_dMin = Math.min(m_dMin, dValue);

      m_dStdDev = Math.sqrt(m_dVariance);

      m_dRMS = Math.sqrt(m_dRMS / m_iCount);

   }

   /**

    * Returns the coefficient of variation

    * 

    * @return the coefficient of variation

    */

   public double getCoeffOfVar() {

      return m_dVariance / m_dMean;

   }

   /**

    * Return the number of values added

    * 

    * @return the number of values added

    */

   public int getCount() {

      return m_iCount;

   }

   /**

    * Returns the maximum value

    * 

    * @return the maximum value

    */

   public double getMax() {

      return m_dMax;

   }

   /**

    * Returns the mean value

    * 

    * @return the mean value

    */

   public double getMean() {

      return m_dMean;

   }

   /**

    * Returns the minimum value

    * 

    * @return the minimum value

    */

   public double getMin() {

      return m_dMin;

   }

   /**

    * Returns the Root Mean Squared

    * 

    * @return the Root Mean Squared

    */

   public double getRMS() {

      return m_dRMS;

   }

   /**

    * Returns the standard deviation

    * 

    * @return the standard deviation

    */

   public double getStdDev() {

      return m_dStdDev;

   }

   /**

    * Returns the sum of all values

    * 

    * @return the sum of all values

    */

   public double getSum() {

      return m_dSum;

   }

   /**

    * Returns the variance

    * 

    * @return the variance

    */

   public double getVariance() {

      return m_dVariance;

   }

}