Preface: First time working with GIS data.
I'm using python's Basemap library for overlaying data on maps.
The tutorial I'm using includes a shapefile for London (london_wards.shp).
I use the bounds method to get the minimum bounding rectangle.
s="/data/london_wards.shp" shp = fiona.open(s) shp.bounds
(-0.5103750689005356, 51.28676016315085, 0.3340155643740321, 51.691874116909894)
This is the latitude, longitude (51.5072° N, 0.1275° W) for London.
I pass these bounds to a basemap instance.
Next, I've done the same for shapefiles obtained from SF OpenData.
However, the bounds are apparently not latitude, longitude.
s="/data/sfpd_districts.shp" shp = fiona.open(s) shp.bounds
(5979385.3163340045, 2085856.3243659574, 6024751.466714004, 2131290.9014959573)
So, I can't pass them to basemap.
Several shapefiles from SF OpenData have similar units returned from shp.bounds.
What are these values?
How are they converted to latitude, longitude for further use?