def masked_all_like(arr): """Return an empty masked array of the same shape and dtype as the array `a`, where all the data are masked. """ a = np.empty_like(arr).view(MaskedArray) a._mask = np.ones(a.shape, dtype=make_mask_descr(a.dtype)) return a
def masked_all(shape, dtype=float): """Return an empty masked array of the given shape and dtype, where all the data are masked. Parameters ---------- dtype : dtype, optional Data type of the output. """ a = masked_array(np.empty(shape, dtype), mask=np.ones(shape, make_mask_descr(dtype))) return a
def masked_all_like(arr): """ Empty masked array with the properties of an existing array. Return an empty masked array of the same shape and dtype as the array `arr`, where all the data are masked. Parameters ---------- arr : ndarray An array describing the shape and dtype of the required MaskedArray. Returns ------- a : MaskedArray A masked array with all data masked. Raises ------ AttributeError If `arr` doesn't have a shape attribute (i.e. not an ndarray) See Also -------- masked_all : Empty masked array with all elements masked. Examples -------- >>> import numpy.ma as ma >>> arr = np.zeros((2, 3), dtype=np.float32) >>> arr array([[ 0., 0., 0.], [ 0., 0., 0.]], dtype=float32) >>> ma.masked_all_like(arr) masked_array(data = [[-- -- --] [-- -- --]], mask = [[ True True True] [ True True True]], fill_value=1e+20) The dtype of the masked array matches the dtype of `arr`. >>> arr.dtype dtype('float32') >>> ma.masked_all_like(arr).dtype dtype('float32') """ a = np.empty_like(arr).view(MaskedArray) a._mask = np.ones(a.shape, dtype=make_mask_descr(a.dtype)) return a
def masked_all(shape, dtype=float): """ Empty masked array with all elements masked. Return an empty masked array of the given shape and dtype, where all the data are masked. Parameters ---------- shape : tuple Shape of the required MaskedArray. dtype : dtype, optional Data type of the output. Returns ------- a : MaskedArray A masked array with all data masked. See Also -------- masked_all_like : Empty masked array modelled on an existing array. Examples -------- >>> import numpy.ma as ma >>> ma.masked_all((3, 3)) masked_array(data = [[-- -- --] [-- -- --] [-- -- --]], mask = [[ True True True] [ True True True] [ True True True]], fill_value=1e+20) The `dtype` parameter defines the underlying data type. >>> a = ma.masked_all((3, 3)) >>> a.dtype dtype('float64') >>> a = ma.masked_all((3, 3), dtype=np.int32) >>> a.dtype dtype('int32') """ a = masked_array(np.empty(shape, dtype), mask=np.ones(shape, make_mask_descr(dtype))) return a