# Source code for mars.tensor.base.moveaxis

```
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright 1999-2021 Alibaba Group Holding Ltd.
#
# 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
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# 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.
# See the License for the specific language governing permissions and
# limitations under the License.
from numpy.core.numeric import normalize_axis_tuple
from ..datasource import tensor as astensor
from .transpose import transpose
[docs]def moveaxis(a, source, destination):
"""
Move axes of a tensor to new positions.
Other axes remain in their original order.
Parameters
----------
a : Tensor
The tensor whose axes should be reordered.
source : int or sequence of int
Original positions of the axes to move. These must be unique.
destination : int or sequence of int
Destination positions for each of the original axes. These must also be
unique.
Returns
-------
result : Tensor
Array with moved axes. This tensor is a view of the input tensor.
See Also
--------
transpose: Permute the dimensions of an array.
swapaxes: Interchange two axes of an array.
Examples
--------
>>> import mars.tensor as mt
>>> x = mt.zeros((3, 4, 5))
>>> mt.moveaxis(x, 0, -1).shape
(4, 5, 3)
>>> mt.moveaxis(x, -1, 0).shape
(5, 3, 4),
These all achieve the same result:
>>> mt.transpose(x).shape
(5, 4, 3)
>>> mt.swapaxes(x, 0, -1).shape
(5, 4, 3)
>>> mt.moveaxis(x, [0, 1], [-1, -2]).shape
(5, 4, 3)
>>> mt.moveaxis(x, [0, 1, 2], [-1, -2, -3]).shape
(5, 4, 3)
"""
a = astensor(a)
source = normalize_axis_tuple(source, a.ndim, "source")
destination = normalize_axis_tuple(destination, a.ndim, "destination")
if len(source) != len(destination):
raise ValueError(
"`source` and `destination` arguments must have "
"the same number of elements"
)
order = [n for n in range(a.ndim) if n not in source]
for dest, src in sorted(zip(destination, source)):
order.insert(dest, src)
return transpose(a, order)
```