Using gammapy.maps to create a WCS, a HEALPix and a region based data structures. The initialization parameters include consistently the positions of the center of the map, the pixel size, the extend of the map as well as the energy axis definition. The energy minimum and maximum values for the creation of the MapAxis object can be defined as strings also specifying the unit. Region definitions can be passed as strings following the DS9 region specifications http://ds9.si.edu/doc/ref/region.html. The output of the code example is shown in Fig. A.3.