def rpy2():
        '''Lazily import the rpy2 module'''
        if LazyImport.rpy2_module is None:
            try:
                rpy2 = __import__('rpy2.robjects')
            except ImportError:
                raise ImportError('The rpy2 module is required')
            LazyImport.rpy2_module = rpy2
            try:
                rpy2.forecast = rpy2.robjects.packages.importr('forecast')
            except:
                raise ImportError('R and the "forecast" package are required')
            rpy2.ts = rpy2.robjects.r['ts']
            __import__('rpy2.robjects.numpy2ri')
            rpy2.robjects.numpy2ri.activate()
        return LazyImport.rpy2_module
Lazily import the rpy2 module