I have worked with all three databases and done migrations between them, so hopefully I can still add something to an old post. Ten years ago I was tasked with putting a largish — 450 million spatial objects — dataset from GML to a spatial database. I decided to try out MySQL and Postgis, at … Read more
If you care about file size or topology, then use TopoJSON. If you don’t care about either, then use GeoJSON for simplicity’s sake. The primary advantage of TopoJSON is size. By eliminating redundancy and using a more efficent fixed-precision integer encoding of coordinates, TopoJSON files are often an order of magnitude smaller than GeoJSON files. … Read more
Needed to convert answers from radians back to degrees. Working code below: import math R = 6378.1 #Radius of the Earth brng = 1.57 #Bearing is 90 degrees converted to radians. d = 15 #Distance in km #lat2 52.20444 – the lat result I’m hoping for #lon2 0.36056 – the long result I’m hoping for. … Read more
EPSG:4326 specifically states that the coordinate order should be latitude, longitude. Many software packages still use longitude, latitude ordering. This situation has wreaked unimaginable havoc on project deadlines and programmer sanity. The best guidance one can offer is to be fully aware of the expected axis order of each component in your software stack. PostGIS … Read more
Create your points using Point values of Geometry data types in MyISAM table. As of Mysql 5.7.5, InnoDB tables now also support SPATIAL indices. Create a SPATIAL index on these points Use MBRContains() to find the values: SELECT * FROM table WHERE MBRContains(LineFromText(CONCAT( ‘(‘ , @lon + 10 / ( 111.1 / cos(RADIANS(@lat))) , ‘ … Read more