transpose
Returns an array with axes transposed.
numpy.transpose(a, axes=None)
axes
tuple or list of ints
default:"None"
If specified, it must be a tuple or list which contains a permutation of [0, 1, …, N-1] where N is the number of axes of a. Negative indices can also be used. The i-th axis of the returned array will correspond to the axis numbered axes[i] of the input. If not specified, defaults to range(a.ndim)[::-1], which reverses the order of the axes.
ndarray - a with its axes permuted. A view is returned whenever possible.
Examples
import numpy as np
# 2D array transpose
a = np.array([[1, 2], [3, 4]])
print(np.transpose(a))
# array([[1, 3],
# [2, 4]])
# 3D array with specified axes
x = np.ones((1, 2, 3))
print(np.transpose(x, (1, 0, 2)).shape)
# (2, 1, 3)
# Reverse all axes (default behavior)
print(np.transpose(x).shape)
# (3, 2, 1)
See Also
ndarray.T - Shorthand for transposemoveaxis - Move axes to new positionsswapaxes - Interchange two axes
ndarray.T
View of the transposed array.
For a 1-D array, this returns an unchanged view of the original array. For a 2-D array, this is the standard matrix transpose. For an n-D array, if axes are not provided, it reverses the order of the axes.
Examples
import numpy as np
a = np.array([[1, 2], [3, 4]])
print(a.T)
# array([[1, 3],
# [2, 4]])
# 1-D array returns unchanged
x = np.array([1, 2, 3])
print(x.T)
# array([1, 2, 3])
# Multi-dimensional
y = np.ones((2, 3, 4))
print(y.T.shape)
# (4, 3, 2)
See Also
transpose - Permute the dimensions of an arrayndarray.transpose - Equivalent method with more options
swapaxes
Interchange two axes of an array.
numpy.swapaxes(a, axis1, axis2)
ndarray - A view of the array with axes swapped (when possible).
Examples
import numpy as np
# Simple 2D swap
x = np.array([[1,2,3]])
print(np.swapaxes(x, 0, 1))
# array([[1],
# [2],
# [3]])
# 3D array swap
x = np.array([[[0,1],[2,3]],[[4,5],[6,7]]])
print(x.shape)
# (2, 2, 2)
print(np.swapaxes(x, 0, 2).shape)
# (2, 2, 2)
print(np.swapaxes(x, 0, 2))
# array([[[0, 4],
# [2, 6]],
# [[1, 5],
# [3, 7]]])
See Also
transpose - Permute axes of an arraymoveaxis - Move axes to new positions
moveaxis
Move axes of an array to new positions.
numpy.moveaxis(a, source, destination)
The array whose axes should be reordered.
Original positions of the axes to move. These must be unique.
Destination positions for each of the original axes. These must also be unique.
ndarray - Array with moved axes. This array is a view of the input array.
Examples
import numpy as np
x = np.zeros((3, 4, 5))
# Move axis 0 to position -1 (last)
print(np.moveaxis(x, 0, -1).shape)
# (4, 5, 3)
# Move axis -1 to position 0 (first)
print(np.moveaxis(x, -1, 0).shape)
# (5, 3, 4)
# Move multiple axes
print(np.moveaxis(x, [0, 1], [-1, -2]).shape)
# (5, 4, 3)
# Equivalent to transpose
print(np.moveaxis(x, [0, 1, 2], [-1, -2, -3]).shape)
# (5, 4, 3)
print(np.transpose(x).shape)
# (5, 4, 3)
See Also
transpose - Permute the dimensions of an arrayswapaxes - Interchange two axes of an array
