numpy.expand_dims¶
- numpy.expand_dims(a, axis)[source]¶
Expand the shape of an array.
Insert a new axis, corresponding to a given position in the array shape.
Parameters: a : array_like
Input array.
axis : int
Position (amongst axes) where new axis is to be inserted.
Returns: res : ndarray
Output array. The number of dimensions is one greater than that of the input array.
See also
Examples
>>> x = np.array([1,2]) >>> x.shape (2,)
The following is equivalent to x[np.newaxis,:] or x[np.newaxis]:
>>> y = np.expand_dims(x, axis=0) >>> y array([[1, 2]]) >>> y.shape (1, 2)
>>> y = np.expand_dims(x, axis=1) # Equivalent to x[:,newaxis] >>> y array([[1], [2]]) >>> y.shape (2, 1)
Note that some examples may use None instead of np.newaxis. These are the same objects:
>>> np.newaxis is None True