def det(a):
    return a[0][0]*a[1][1]*a[2][2] + a[0][1]*a[1][2]*a[2][0] + a[0][2]*a[1][0]*a[2][1] - a[0][2]*a[1][1]*a[2][0] - a[0][1]*a[1][0]*a[2][2] - a[0][0]*a[1][2]*a[2][1]
Tests out the GEOSBase class.
dataset/ETHPy150Open tudelft3d/CityGML2OBJs/polygon3dmodule.py/det--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/django/contrib/gis/geos/tests/test_geos.py/GEOSTest.test00_base