Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.morphometry.elevationReliefIndex;

import es.unex.sextante.core.GeoAlgorithm;

import es.unex.sextante.core.AnalysisExtent;

import es.unex.sextante.core.Sextante;

import es.unex.sextante.dataObjects.IRasterLayer;

import es.unex.sextante.exceptions.GeoAlgorithmExecutionException;

import es.unex.sextante.exceptions.RepeatedParameterNameException;

public class ElevationReliefIndexAlgorithm

         extends

            GeoAlgorithm {

   private final static int   m_iOffsetX[] = { 0, 1, 1, 1, 0, -1, -1, -1 };

   private final static int   m_iOffsetY[] = { 1, 1, 0, -1, -1, -1, 0, 1 };

   public static final String DEM          = "DEM";

   public static final String RESULT       = "RESULT";

   IRasterLayer               m_ERIndex;

   IRasterLayer               m_DEM        = null;

   @Override

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      int x, y;

      int iNX, iNY;

      m_DEM = m_Parameters.getParameterValueAsRasterLayer(DEM);

      m_ERIndex = getNewRasterLayer(RESULT, Sextante.getText("Elevation-relief_ratio"), IRasterLayer.RASTER_DATA_TYPE_FLOAT);

      final AnalysisExtent extent = m_ERIndex.getWindowGridExtent();

      m_DEM.setWindowExtent(extent);

      iNX = m_DEM.getNX();

      iNY = m_DEM.getNY();

      for (y = 0; (y < iNY) && setProgress(y, iNY); y++) {

         for (x = 0; x < iNX; x++) {

            calculateERIndex(x, y);

         }

      }

      return !m_Task.isCanceled();

   }

   @Override

   public void defineCharacteristics() {

      setName(Sextante.getText("Elevation-relief_ratio"));

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

      setUserCanDefineAnalysisExtent(true);

      try {

         m_Parameters.addInputRasterLayer(DEM, Sextante.getText("Elevation"), true);

         addOutputRasterLayer(RESULT, Sextante.getText("Elevation-relief_ratio"));

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

   }

   private void calculateERIndex(final int x,

                                 final int y) {

      int i;

      int iCells;

      double z, dAvgZ;

      double dMaxZ, dMinZ;

      double dIndex;

      z = m_DEM.getCellValueAsDouble(x, y);

      if (m_DEM.isNoDataValue(z)) {

         m_ERIndex.setNoData(x, y);

      }

      else {

         dMaxZ = dMinZ = z;

         dAvgZ = z;

         iCells = 0;

         for (i = 0; i < 8; i++) {

            z = m_DEM.getCellValueAsDouble(x + m_iOffsetX[i], y + m_iOffsetY[i]);

            if (!m_DEM.isNoDataValue(z)) {

               iCells++;

               dAvgZ += z;

               dMinZ = Math.min(dMinZ, z);

               dMaxZ = Math.max(dMaxZ, z);

            }

         }

         if (iCells == 0) {

            m_ERIndex.setNoData(x, y);

         }

         else {

            if (dMaxZ != dMinZ) {

               dIndex = (dAvgZ - dMinZ) / (dMaxZ - dMinZ);

               m_ERIndex.setCellValue(x, y, dIndex);

            }

            else {

               m_ERIndex.setNoData(x, y);

            }

         }

      }

   }

}