Hi there, Here is a structured array with 3 fields each of which has 3 fields in turn:
In [3]: desc = [('a',int), ('b',int), ('c',int)] In [4]: desc = [('x',desc), ('y',desc), ('z',desc)] With a regular ndarray it works just fine: In [11]: x = np.zeros(2, dtype=desc) In [12]: x['x']['b'] = 2 In [13]: x['x']['b'] Out[13]: array([2, 2]) However if try the same with a masked array, it fails: In [14]: x = np.ma.masked_all(2, dtype=desc) In [15]: x['x']['b'] = 2 --------------------------------------------------------------------------- ValueError Traceback (most recent call last) /home/ernest/<ipython console> in <module>() /usr/lib/python2.5/site-packages/numpy/ma/core.pyc in __setitem__(self, indx, value) 1574 if self._mask is nomask: 1575 self._mask = make_mask_none(self.shape, self.dtype) -> 1576 ndarray.__setitem__(self._mask, indx, getmask(value)) 1577 return 1578 #........................................ ValueError: field named b not found. Any idea of what the problem is? Ernest _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion