Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.gridCalculus.gridFromFunction;

import org.nfunk.jep.JEP;

import es.unex.sextante.additionalInfo.AdditionalInfoNumericalValue;

import es.unex.sextante.core.GeoAlgorithm;

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 GridFromFunctionAlgorithm

         extends

            GeoAlgorithm {

   public static final String MINX    = "MINX";

   public static final String MINY    = "MINY";

   public static final String MAXX    = "MAXX";

   public static final String MAXY    = "MAXY";

   public static final String FORMULA = "FORMULA";

   public static final String RESULT  = "RESULT";

   @Override

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      int x, y;

      int iNX, iNY;

      double dx, dy;

      double dMinX, dMinY, dMaxX, dMaxY;

      double dRangeX, dRangeY;

      double dValue;

      String sFormula;

      final JEP jep = new JEP();

      IRasterLayer result;

      jep.addStandardConstants();

      jep.addStandardFunctions();

      jep.addVariable("x", 0);

      jep.addVariable("y", 0);

      dMinX = m_Parameters.getParameterValueAsInt(MINX);

      dMinY = m_Parameters.getParameterValueAsInt(MINY);

      dMaxX = m_Parameters.getParameterValueAsInt(MAXX);

      dMaxY = m_Parameters.getParameterValueAsInt(MAXY);

      sFormula = m_Parameters.getParameterValueAsString(FORMULA).toLowerCase();

      dRangeX = dMaxX - dMinX;

      dRangeY = dMaxY - dMinY;

      result = getNewRasterLayer(RESULT, Sextante.getText("Layer_from_function"), IRasterLayer.RASTER_DATA_TYPE_DOUBLE);

      iNX = result.getWindowGridExtent().getNX();

      iNY = result.getWindowGridExtent().getNY();

      jep.parseExpression(sFormula);

      if (!jep.hasError()) {

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

            dy = dMinY + dRangeY * ((double) y / (double) iNY);

            jep.addVariable("y", dy);

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

               dx = dMinX + dRangeX * ((double) x / (double) iNX);

               jep.addVariable("x", dx);

               dValue = jep.getValue();

               result.setCellValue(x, y, dValue);

            }

         }

      }

      else {

         throw new GeoAlgorithmExecutionException(Sextante.getText("Wrong_formula"));

      }

      return !m_Task.isCanceled();

   }

   @Override

   public void defineCharacteristics() {

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

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

      setUserCanDefineAnalysisExtent(true);

      try {

         m_Parameters.addNumericalValue(MINX, "X min", -1, AdditionalInfoNumericalValue.NUMERICAL_VALUE_DOUBLE);

         m_Parameters.addNumericalValue(MAXX, "X Max", 1, AdditionalInfoNumericalValue.NUMERICAL_VALUE_DOUBLE);

         m_Parameters.addNumericalValue(MINY, "Y Min", -1, AdditionalInfoNumericalValue.NUMERICAL_VALUE_DOUBLE);

         m_Parameters.addNumericalValue(MAXY, "Y Max", 1, AdditionalInfoNumericalValue.NUMERICAL_VALUE_DOUBLE);

         m_Parameters.addString(FORMULA, Sextante.getText("Formula"));

         addOutputRasterLayer(RESULT, Sextante.getText("Grid_from_function"));

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

   }

}