# from `bindings/python/examples/france.py`frompathlibimportPathimportnumpyasnpimportnumpy.randomasnrfromdatovizimportcanvas,run,colormapROOT=Path(__file__).resolve().parent.parent.parent.parentpos=np.fromfile(ROOT/"data/misc/departements.polypoints.bin",dtype=np.float64)pos=pos.reshape((-1,2))pos=np.c_[pos[:,1],pos[:,0],np.zeros(pos.shape[0])]# latitude, longitude, 0# Web Mercator projectionlat,lon,_=pos.Tlonrad=lon/180.0*np.pilatrad=lat/180.0*np.pizoom=1c=256/2*np.pi*2**zoomx=c*(lonrad+np.pi)y=-c*(np.pi-np.log(np.tan(np.pi/4.0+latrad/2.0)))pos=np.c_[x,y,_]length=np.fromfile(ROOT/"data/misc/departements.polylengths.bin",dtype=np.uint32)N=len(length)color=colormap(nr.rand(N),vmin=0,vmax=1,cmap='viridis')c=canvas(show_fps=False)panel=c.panel(controller='axes')visual=panel.visual('polygon')visual.data('pos',pos)visual.data('length',length)visual.data('color',color)run()