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# numpy.ma.is_masked

`numpy.ma.``is_masked`(x)

  Determine whether input has masked values.

  Accepts any object as input, but always returns False unless the input is a MaskedArray containing masked values.

  Parameters: | x : array_like Array to check for masked values.
  Returns: | result : bool True if x is a MaskedArray with masked values, False otherwise.

  Examples

      >>> import numpy.ma as ma
      >>> x = ma.masked_equal([0, 1, 0, 2, 3], 0)
      >>> x
      masked_array(data = [-- 1 -- 2 3],
            mask = [ True False  True False False],
            fill_value=999999)
      >>> ma.is_masked(x)
      True
      >>> x = ma.masked_equal([0, 1, 0, 2, 3], 42)
      >>> x
      masked_array(data = [0 1 0 2 3],
            mask = False,
            fill_value=999999)
      >>> ma.is_masked(x)
      False

  Always returns False if x isn’t a MaskedArray.

      >>> x = [False, True, False]
      >>> ma.is_masked(x)
      False
      >>> x = 'a string'
      >>> ma.is_masked(x)
      False