Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.gridStatistics.neighborhoodVariance;

import es.unex.sextante.core.Sextante;

import es.unex.sextante.gridStatistics.base.NeighborhoodStatsBaseAlgorithm;

public class NeighborhoodVarianceAlgorithm

         extends

            NeighborhoodStatsBaseAlgorithm {

   @Override

   public void defineCharacteristics() {

      setName(Sextante.getText("Variance__neighbourhood"));

      setGroup(Sextante.getText("Focal_statistics"));

      super.defineCharacteristics();

   }

   @Override

   protected double processValues() {

      int i;

      int iValidCells = 0;

      double dValue;

      double dSum = 0;

      double dVar = 0;

      for (i = 0; i < m_dValues.length; i++) {

         dValue = m_dValues[i];

         if (dValue != NO_DATA) {

            dSum += dValue;

            dVar += (dValue * dValue);

            iValidCells++;

         }

      }

      if (iValidCells > 0) {

         final double dMean = dSum / iValidCells;

         return (dVar / iValidCells - dMean * dMean);

      }

      else {

         return NO_DATA;

      }

   }

}