Το WKT είναι μια μορφή αναπαράστασης γεωμετριών σε κείμενο, που χρησιμοποιείται σε βάσεις δεδομένων (PostGIS, SpatiaLite) και εφαρμογές GIS. Απλό και εύκολο στην ενσωμάτωση.
Βασικά χαρακτηριστικά
Σχετικά με τη μορφή WKT
WKT (Well-Known Text) is the textual encoding of geometry from the OGC standard: POINT(37.6177 55.7558), LINESTRING(...), POLYGON((...)). It is understood by every spatial database and library — PostGIS, SpatiaLite, Shapely, JTS, GEOS — and it can be read by eye, which makes the format indispensable while debugging.
The export is taken when geometry is needed as text: to paste into an SQL query, to put into a test, to pass coordinates to someone else's system, to take a quick look at what came out of the selected area at all.
The output is a single text file in UTF-8. At the top are comments with the bounding box of the area and the coordinate system, then it goes layer by layer: a line like "-- layer: roads" with one geometry per line underneath it. Coordinates are in WGS84 (EPSG:4326) with six decimal places — that is about ten centimeters on the ground.
One important thing: WKT stores shapes only. There are no names, types or other OpenStreetMap tags in the file — if you need attributes, take GeoJSON, GeoPackage or a CSV with a WKT column.
Ποιο πρόγραμμα ανοίγει αρχεία WKT
Τα ακόλουθα προγράμματα και εφαρμογές μπορούν να ανοίξουν, να επεξεργαστούν και να εργαστούν με αρχεία WKT (Well-Known Text) (.wkt) που έχουν εξαχθεί από το OSM2CDR:
Format specifications
- Open standard
- 3D coordinates supported
- Lossless (no quality loss)
- No attributes
- Output: 1 file
- Well-Known Text (OGC Simple Features). One geometry per line, human-readable. Direct INSERT into PostGIS / Spatialite.
Ποιοι χρησιμοποιούν χάρτες WKT
Πώς να εξαγάγετε WKT
Πώς να το ανοίξετε μετά την εξαγωγή
- PostGIS — paste the lines as they are: INSERT ... VALUES (ST_GeomFromText('POLYGON((...))', 4326)); the SRID must be specified.
- Python — from shapely import wkt, then wkt.loads(line) line by line, skipping the lines that begin with two hyphens.
- QGIS — the QuickWKT plugin pastes geometry from the clipboard onto a temporary layer; for a full-fledged layer it is easier to download GeoJSON right away.
- Tables — WKT is understood by CSV import in QGIS: "Add Delimited Text Layer", with geometry from the WKT field.
- Checking — ST_IsValid in PostGIS or shapely.is_valid: self-intersections after simplification do happen, and it is better to learn about them before loading into a database.
Δημοφιλείς χάρτες σε WKT
Αποκτήστε εξαγωγές χαρτών WKT (Well-Known Text)
Κατεβάστε επαγγελματικούς χάρτες WKT από το OpenStreetMap. Άμεση δημιουργία, για οποιαδήποτε περιοχή.
Συχνές ερωτήσεις
Σύγκριση με άλλες μορφές
Σχετικές μορφές
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