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Mastering Geospatial Analysis with Python
book

Mastering Geospatial Analysis with Python

by Silas Toms, Paul Crickard, Eric van Rees
April 2018
Beginner to intermediate content levelBeginner to intermediate
440 pages
11h 36m
English
Packt Publishing
Content preview from Mastering Geospatial Analysis with Python

Changing the CRS

The data in the database is using World Geodetic System 84 (WGS 84), latitude and longitude. What if you need the data out in European Petroleum Survey Group (EPSG) 3857? You can change the spatial reference in your query using ST_Transform(). The following code shows you how by using PostGIS functions:

cursor.execute("SELECT UpdateGeometrySRID('art_pieces','location',4326)")cursor.execute("SELECT Find_SRID('public','art_pieces','location')")cursor.fetchall()

The previous code makes two queries to the database:

  • Firstly, it assigns a spatial reference system identifier to the geometry column in the table using UpdateGeomtrySRID(). This needs to be done because the points were put in the table without any reference to an ...
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Publisher Resources

ISBN: 9781788293334Supplemental Content