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proxMatrixAndSpatialStatistics.cpp

Shows how to create a proximity matrix from a Spatial Temporal Element Set (STElementSet) and calculate spatial statistics

    /************************************************************************************
    TerraLib - a library for developing GIS applications.
    Copyright © 2001-2004 INPE and Tecgraf/PUC-Rio.

    This code is part of the TerraLib library.
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    You should have received a copy of the GNU Lesser General Public
    License along with this library.

    The authors reassure the license terms regarding the warranties.
    They specifically disclaim any warranties, including, but not limited to,
    the implied warranties of merchantability and fitness for a particular purpose.
    The library provided hereunder is on an "as is" basis, and the authors have no
    obligation to provide maintenance, support, updates, enhancements, or modifications.
    In no event shall INPE and Tecgraf / PUC-Rio be held liable to any party for direct,
    indirect, special, incidental, or consequential damages arising out of the use
    of this library and its documentation.
    *************************************************************************************/

    /*
       This file illustrates an example of how to create a proximity matrix from a
       Spatial Temporal Element Set (STElementSet) and calculate spatial statistics.
       In this example, the adjacency strategy is used to construct the matrix.

       Author: Karine Reis
    */

    #include "../../src/terralib/kernel/TeSTElementSet.h"
    #include "../../src/terralib/kernel/TeSTEFunctionsDB.h"
    #include "../../src/terralib/kernel/TeGeneralizedProxMatrix.h"
    #include "../../src/terralib/stat/TeSpatialStatistics.h"
    #include "../../src/terralib/drivers/MySQL/TeMySQL.h"

    int main()
    {
               // Datatabase server parameters
               string host = "localhost";
               string dbname = "DB320RC1";
               string user = "root";
               string password = "vinhas";

               // Open a connection to the DB320RC1 MySQL database
               TeDatabase* db = new TeMySQL();
               if (!db->connect(host, user, password, dbname))
               {
                          cout << "Error: " << db->errorMessage() << endl;
                          cout << endl << "Press Enter\n";
                          getchar();
                          return 1;
               }
               cout << "Connection successful to the database \"" << dbname << "\" on MySQL server \"" << host << "\" !\n";;

               // Opens a connection to a TerraLib database
               // Loads a layer named DistritosSaoPaulo
               TeLayer* DistritosSP =  new TeLayer("Distritos");
               if (!db->loadLayer(DistritosSP))
               {
                   cout << "Fail to load the layer!" << db->errorMessage() << endl;
                          db->close();
                          cout << endl << "Press Enter\n";
                          getchar();
               return 1;
               }

               // Creates a STElementSet from DistritosSP layer
               TeSTElementSet steSet(DistritosSP);

               // Fills the STElementSet only with the attribute "Populac" to calculate statistics
               //and without geometries
               vector<string> attrs;
               attrs.push_back ("Distritos.Pop91");

               if(!TeSTOSetBuildDB(&steSet, false, false, attrs))
               {
                          cout << "Error! " << endl;
                          cout << endl << "Press Enter\n";
                          getchar();
                          return 1;
               }

               // Shows how many elements the elementSet has
               cout << "Number of elements: " <<  steSet.numElements() << endl;

               // Constructs the proximity matrix
               TeProxMatrixLocalAdjacencyStrategy                                sc_adj (&steSet, TePOLYGONS);
               TeGeneralizedProxMatrix<TeSTElementSet>                proxMat(&sc_adj);

               cout << "Calculating the proximity matrix..." << endl;
               if(!proxMat.constructMatrix())
               {
                          cout << "Error building proximity matrix! " << endl;
                          return 1;
               }

               // Calculates the global mean
               double mean = TeFirstMoment (steSet.begin(), steSet.end(), 0);
               cout << "Global mean " << mean << endl << endl;

               // Calculates the desviations (Z) to each object and keeps them
               // in the STElementSet
               if(!TeDeviation (steSet.begin(), steSet.end(), mean))
               {
                          cout << "Error calculating Z! " << endl;
                          return 1;
               }

               // Index of the Z (desviations) attribute in the STElementSet
               int indexZ = 1;

               // Calculates the local mean (WZ) to each object and keeps them
               // in the STElementSet
               if(!TeLocalMean (&steSet, &proxMat, indexZ))
               {
                          cout << "Error calculating Local Mean! " << endl;
                          return 1;
               }

               // Index of the WZ (local mean) attribute in the STElementSet
               int indexWZ = 2;

               // Shows the Z and WZ generated for each object
               TeSTElementSet::iterator it = steSet.begin();
               while ( it != steSet.end())
               {
                          TeSTInstance obj = (*it);

          //Gets attribute value
                          string valZ, valWZ;
                          obj.getPropertyValue(valZ, indexZ);
                          obj.getPropertyValue(valWZ, indexWZ);
                          cout << " Object Identifier :  " << obj.objectId() << endl;
                          cout << " Z                      :  " << valZ   << endl;
                          cout << " WZ          :  " << valWZ  << endl << endl;
                          ++it;
               }

               // Inserts the generated attributes (Z and WZ) in the DistritosSP
               // table
               if(!TeUpdateDBFromSet (&steSet, "Distritos"))
               {
                          cout << "Error updating database! " << endl;
                          return 1;
               }

               db->close();
               cout << endl << "Press Enter\n";
               getchar();
               return 0;
    }

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