astropy/astropy — pull request #421 by wkerzendorf (2012-10-10 21:52:32+00:00)
Title: NDData initialize from NDData objects (goes also for NDError)

Example
```python
d1 = NDData(np.ones((5, 5)))
d2 = NDData(d1, copy=False)

e1 = StandardDeviationError(np.ones((5, 5)) * 3)
e2 = StandardDeviationError(e1, copy=False)
```