Is it possible to take the gradient between two points that are more than one element apart?
A simple array:
f = np.array([4,5,8,1,5,3,2,5])
I want to program the following:
At boundaries: One-sides as used by np.gradient
Values next to boundary values: Central differences as used by np.gradient for interior points
For the interior points
((i-2)-(i+2))/4
The resulting arry:
f_res = np.array([1,2,0.25,-0.5,-1.5,1,1,3])
Documentation for np.gradient: numpy.gradient
You could easily compute this manually:
N = 2
out = np.gradient(f)
out[N:-N] = (f[2*N:]-f[:-2*N])/4
Output:
array([ 1. , 2. , 0.25, -0.5 , -1.5 , 1. , 1. , 3. ])