Working and managing numpy arrays with numba

Why can't Numba jit compile a simple Numpy array operation?

Here is a minimal non-working example that reproduces Numba compilation failure

import numpy as np
from numba import jit

rows = 10
columns = 999999
A = np.empty((rows, columns))
b = np.linspace(0, 1, num=rows)

@jit(nopython=True)
def replicate(A, b):
    for i in range(A.shape[1]):
        A[:, i] = b
    return A #optional

replicate(a, b)

      

With the following error:

TypingError: Failed at nopython (nopython frontend)
Cannot resolve setitem: array(float64, 1d, C, nonconst)[(slice3_type, int64)] = array(float64, 1d, C, nonconst)
File "<ipython-input-32-db24fbe2922f>", line 12

      

Am I doing something wrong?

As an aside, I need nopython mode because in my actual situation I need to perform array addition, scalar multiplication, and an array populated with other arrays. and I understand that in object mode I will not be able to do loop jitter and therefore I will not see any real performance improvement on runtime.

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1 answer


Numba does not support numpy slicing in mode nopython

. Try expanding the loops explicitly:



rows = 10
columns = 999999
a = np.empty((rows, columns))
b = np.linspace(0, 1, num=rows)

@jit(nopython=True)
def replicate(A, b):
    for i in xrange(A.shape[0]):
        for j in xrange(A.shape[1]):
            A[i, j] = b[i]
    return A #optional

replicate(a, b)

      

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