# numpy.ma.masked_array.cumsum

`masked_array.``cumsum`(axis=None, dtype=None, out=None)

  Return the cumulative sum of the array elements over the given axis.

  Masked values are set to 0 internally during the computation. However, their position is saved, and the result will be masked at the same locations.

  Refer to `numpy.cumsum` for full documentation.

  See also

  `ndarray.cumsum`
    corresponding function for ndarrays
  `numpy.cumsum`
    equivalent function

  Notes

  The mask is lost if out is not a valid `MaskedArray` !

  Arithmetic is modular when using integer types, and no error is raised on overflow.

  Examples

      >>> marr = np.ma.array(np.arange(10), mask=[0,0,0,1,1,1,0,0,0,0])
      >>> print(marr.cumsum())
      [0 1 3 -- -- -- 9 16 24 33]