What is a pythonic way to access the shifted, either right or left, of a numpy array? A clear example:
a = np.array([1.0, 2.0, 3.0, 4.0])
Is there away to access:
a_shifted_1_left = np.array([2.0, 3.0, 4.0, 1.0])
from the numpy library?
1 Answer
You are looking for np.roll -
np.roll(a,-1) # shifted left
np.roll(a,1) # shifted right
Sample run -
In [28]: a
Out[28]: array([ 1., 2., 3., 4.])
In [29]: np.roll(a,-1) # shifted left
Out[29]: array([ 2., 3., 4., 1.])
In [30]: np.roll(a,1) # shifted right
Out[30]: array([ 4., 1., 2., 3.])
If you want more shifts, just go np.roll(a,-2) and np.roll(a,2) and so on.
