code: def ebeam(self, context):
          
          if context.shape != self.shape:
              raise ValueError("Partial feeding of the "
                  "beam cube is not yet supported %s %s." % (context.shape, self.shape))
  
          ebeam = np.empty(context.shape, context.dtype)
  
          # Iterate through the correlations,
          # assigning real and imaginary data, if present,
          # otherwise zeroing the correlation
          for i, (re, im) in enumerate(self._files.itervalues()):
              ebeam[:,:,:,i].real[:] = 0 if re is None else re[0].data.T
              ebeam[:,:,:,i].imag[:] = 0 if im is None else im[0].data.T
  
          return ebeam
docs: ebeam cube data source