Center window and same length output

[matiasandina]

I'm not sure whether this is in the documentation somewhere and I missed it, but I am trying to replicate the behavior of pandas rolling function:

.rolling(3, center=True, min_periods=0)

From the minimal example in the docs:

import numpy as np
import numpy_ext as npext

a = np.array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
window = 3
npext.rolling_apply(np.sum, window, a, prepend_nans=True)
array([nan, nan,  3.,  6.,  9., 12., 15., 18., 21., 24.])
npext.rolling_apply(np.sum, window, a, prepend_nans=False)
array([ 3,  6,  9, 12, 15, 18, 21, 24])

Is there a way to get the result to match this pandas version?

pd.DataFrame(a).rolling(3, center=True, min_periods=0).apply(np.sum).values.flatten()
array([ 1.,  3.,  6.,  9., 12., 15., 18., 21., 24., 17.])