# Source code for mars.tensor.base.setdiff1d

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#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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[docs]def setdiff1d(ar1, ar2, assume_unique=False):
"""
Find the set difference of two tensors.

Return the unique values in `ar1` that are not in `ar2`.

Parameters
----------
ar1 : array_like
Input tensor.
ar2 : array_like
Input comparison tensor.
assume_unique : bool
If True, the input tensors are both assumed to be unique, which
can speed up the calculation.  Default is False.

Returns
-------
setdiff1d : Tensor
1D tensor of values in `ar1` that are not in `ar2`. The result
is sorted when `assume_unique=False`, but otherwise only sorted
if the input is sorted.

Examples
--------
>>> import mars.tensor as mt
>>> a = mt.array([1, 2, 3, 2, 4, 1])
>>> b = mt.array([3, 4, 5, 6])
>>> mt.setdiff1d(a, b).execute()
array([1, 2])

"""

from ..datasource.array import asarray
from .in1d import in1d
from .unique import unique

if assume_unique:
ar1 = asarray(ar1).ravel()
else:
ar1 = unique(ar1)
ar2 = unique(ar2)
return ar1[in1d(ar1, ar2, assume_unique=True, invert=True)]
```