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| {{Upravit}} | | {{freegiswiki|OGR / Ukázka použití}} |
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| Tato stránka obsahuje ukázku zdrojového textu demonstračního programu využívající pro přístup k vektorovým datům knihovnu '''[[GDAL/OGR|OGR]]'''. Program je inspirován skriptem z [[153GIS2 2009 - 10. cvičení#1|cvičení GIS2]].
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| __TOC__
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| == C++ ==
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| <source lang="cpp">
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| #include <iostream>
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| #include "ogrsf_frmts.h"
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| using std::cout;
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| using std::cerr;
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| using std::endl;
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| int main(int argc, char **argv)
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| {
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| const char *filename;
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|
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| OGRDataSource *poDS;
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| OGRLayer *poLayer;
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| OGRFeatureDefn *poFDefn;
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| if (argc != 2) {
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| cerr << "Pouziti: " << argv[0] << " shapefile" << endl;
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| return 1;
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| }
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|
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| filename = argv[1];
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|
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| // registrovat dostupne OGR ovladace
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| OGRRegisterAll();
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| // otevrit ShapeFile pro cteni
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| poDS = OGRSFDriverRegistrar::Open(filename, FALSE);
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| if (poDS == NULL) {
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| cerr << "Otevreni '" << filename << "' selhalo." << endl;
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| return 1;
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| }
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|
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| // nacist prvni OGR vrstvu (tj. Shapefile)
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| poLayer = poDS->GetLayer(0);
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| if (poLayer == NULL) {
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| cerr << "Nelze nacist OGR vrstvu." << endl;
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| return 1;
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| }
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| // ziskat informace o vrstve
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| poFDefn = poLayer->GetLayerDefn();
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| cout << "Detekovana OGR vrstva '" << poFDefn->GetName() << "'.\n\n";
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| for(int iField = 0; iField < poFDefn->GetFieldCount(); iField++) {
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| // ziskat informace o atributovem sloupci
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| OGRFieldDefn *poFieldDefn = poFDefn->GetFieldDefn(iField);
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| cout << poFieldDefn->GetNameRef() << endl;
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| }
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| return 0;
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| }
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| </source>
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| == Python ==
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| <source lang="python">
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| import sys
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| import osgeo.ogr as ogr
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| def main():
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| if len(sys.argv) != 2:
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| print >> sys.stderr, "Pouziti: %s shapefile" % sys.argv[0]
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| return 1
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|
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| filename = sys.argv[1]
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| # otevrit ShapeFile pro cteni
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| ds = ogr.Open(filename)
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| if ds is None:
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| print >> sys.stderr, "Otevreni '%s' selhalo." % filename
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| return 1
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| # nacist prvni OGR vrstvu (tj. Shapefile)
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| lyr = ds.GetLayer(0)
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| if lyr is None:
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| print >> sys.stderr, "Nelze nacist OGR vrstvu."
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|
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| # ziskat informace o vrstve
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| feat_defn = lyr.GetLayerDefn()
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| print "Detekovana OGR vrstva '%s'.\n" % feat_defn.GetName()
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| for i in range(feat_defn.GetFieldCount()):
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| field_defn = feat_defn.GetFieldDefn(i)
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| print field_defn.GetNameRef()
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|
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| return 0
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| if __name__ == "__main__":
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| sys.exit(main())
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| </source>
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| == Související články ==
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| * [[153GIS2 2009 - 10. cvičení - GRASS GIS|Ukázka skriptů pro GRASS GIS]]
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| == Externí odkazy ==
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| * [http://gdal.osgeo.org/ogr/hierarchy.html OGR API]
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| * [http://gdal.osgeo.org/ogr/ogr_apitut.html OGR API Tutorial]
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| * [http://gdal.osgeo.org/ogr/ogr_arch.html OGR Architecture]
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| {{GFOSS}}
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| {{Programování}}
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| {{C++}}
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| {{Python}}
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