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# numpy.ma.expand_dims

`numpy.ma.``expand_dims`(x, axis)

  Expand the shape of an array.

  Expands the shape of the array by including a new axis before the one specified by the axis parameter. This function behaves the same as `numpy.expand_dims` but preserves masked elements.

  See also

  `numpy.expand_dims`
    Equivalent function in top-level NumPy module.

  Examples

      >>> import numpy.ma as ma
      >>> x = ma.array([1, 2, 4])
      >>> x[1] = ma.masked
      >>> x
      masked_array(data = [1 -- 4],
                   mask = [False  True False],
             fill_value = 999999)
      >>> np.expand_dims(x, axis=0)
      array([[1, 2, 4]])
      >>> ma.expand_dims(x, axis=0)
      masked_array(data =
       [[1 -- 4]],
                   mask =
       [[False  True False]],
             fill_value = 999999)

  The same result can be achieved using slicing syntax with np.newaxis.

      >>> x[np.newaxis, :]
      masked_array(data =
       [[1 -- 4]],
                   mask =
       [[False  True False]],
             fill_value = 999999)