Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.rasterize.idw;

import es.unex.sextante.additionalInfo.AdditionalInfoNumericalValue;

import es.unex.sextante.closestpts.Point3D;

import es.unex.sextante.core.Sextante;

import es.unex.sextante.exceptions.GeoAlgorithmExecutionException;

import es.unex.sextante.exceptions.RepeatedParameterNameException;

import es.unex.sextante.rasterize.interpolationBase.BaseInterpolationAlgorithm;

public class IDWAlgorithm

         extends

            BaseInterpolationAlgorithm {

   public static final String POWER           = "POWER";

   public static final String CROSSVALIDATION = "CROSSVALIDATION";

   private double             m_dPower;

   @Override

   public void defineCharacteristics() {

      super.defineCharacteristics();

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

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

      try {

         m_Parameters.addNumericalValue(POWER, Sextante.getText("Exponent"), AdditionalInfoNumericalValue.NUMERICAL_VALUE_DOUBLE,

                  2, 0, Double.MAX_VALUE);

         addOutputTable(CROSSVALIDATION, Sextante.getText("Cross_validation"));

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

   }

   @Override

   protected void setValues() throws GeoAlgorithmExecutionException {

      super.setValues();

      m_dPower = m_Parameters.getParameterValueAsDouble(POWER);

   }

   @Override

   protected double interpolate(final double x,

                                final double y) {

      int i;

      int iPts = 0;

      Point3D pt;

      double d;

      double dDistSum = 0, dZSum = 0;

      try {

         if (m_NearestPoints.length != 0) {

            final int iSize = m_NearestPoints.length;

            for (i = 0; i < iSize; i++) {

               if (m_NearestPoints[i] != null) {

                  iPts++;

                  pt = m_NearestPoints[i].getPt();

                  d = m_NearestPoints[i].getDist();

                  if (d <= 0.0) {

                     return pt.getZ();

                  }

                  d = Math.pow(d, -m_dPower);

                  dZSum += d * pt.getZ();

                  dDistSum += d;

               }

            }

            if (iPts > 0) {

               return dZSum / dDistSum;

            }

            else {

               return NO_DATA;

            }

         }

         else {

            return NO_DATA;

         }

      }

      catch (final Exception e) {

         return NO_DATA;

      }

   }

}