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Plugin Spasial Query

The spatialquery Spatial Query Plugin allows you to make a spatial query (i.e., select features) in a target layer with reference to another layer. The functionality is based on the GEOS library and depends on the selected source feature layer.

Operator yang mungkin adalah:

  • Isi

  • Sama

  • Tumpang tindih

  • Persilangan

  • Berpotongan

  • Memisah

  • Bersinggungan

  • Di dalam

Menggunakan plugin

Sebagai contoh, kita ingin mencari daerah dalam dataset Alaska yang mengandung bandara. Langkah-langkah berikut diperlukan:

  1. Start QGIS and load the vector layers regions.shp and airports.shp.
  2. Load the Spatial Query plugin in the Plugin Manager (see The Plugins Dialog) and click on the spatialquery Spatial Query icon, which appears in the QGIS toolbar menu. The plugin dialog appears.

  3. Pilih lapisan regions sebagai sumber lapisan dan airports sebagai lapisan fitur referensi.

  4. Pilih ‘Isi’ sebagai operator dan klik [Terapkan].

Sekarang Anda mendapatkan daftar ID fitur dari query dan Anda memiliki beberapa pilihan seperti yang ditunjukkan pada figure_spatial_query_1.

  • Click on selectesubsetlayer Create layer with list of items.
  • Select an ID from the list and click on selectcreatelayer Create layer with selected.
  • Select ‘Remove from current selection’ in the field And use the result to selectstring.
  • You can checkbox Zoom to item or display checkbox Log messages.
  • Additionally in Result Feature ID’s with the options ‘Invalid source’ and ‘Invalid reference’ you can have a look at features with geometries errors. These features aren’t used for the query.

Figure Spatial Query 1:

../../../_images/spatial_query_sample.png

Spatial Query analysis - regions contain airports nix