Cannot determine ufunc class when targetting parallel or cuda

[Ismael Browne]

I'm learning how to use numba, and so im trying to optimize and make this block of code run faster:

from numba import vectorize,njit

import numpy as np

@vectorize("i2(i8)",target="parallel")

def collatz_step_counter(n):

    count=0

    while n!=1:

        if n%2==0:

            n/=2

        else:

            n=(3*n+1)/2

            count+=1

        count+=1

    return count

@njit

def max_collatz_steps(num,want_data=False):

    max_steps=0

    max_input=0

    lis=np.arange(1,num+1,2,dtype=np.int64)

    lis=collatz_step_counter(lis)

    max_steps=max(lis)

    max_input=2*lis.argmax()+1

    return max_input,max_steps

max_collatz_steps(1000000)

But when I put the @njit decorator on max_collatz_steps, it gives me one of two errors:

-If for the first function I write target="parallel", it gives me this error:

TypingError: cannot determine Numba type of <class 'numpy.ufunc'>

-Instead, if I write target="cuda", it gives me this error:

TypingError: cannot determine Numba type of <class 'numba.cuda.dispatcher.CUDAUFuncDispatcher'>

When I write target="cpu", it works fine.

Thanks in advance.

[Valentin Haenel]

Dear Ismael,

thank you for asking about this issue on the Numba mailinglist. This mailinglist is slowly being retired and so I have copied the issue over to our issue tracker here:

https://github.com/numba/numba/issues/6280

Also,  I can confirm that I observe the behavior you describe.

Best wishes,

V-

--
You received this message because you are subscribed to the Google Groups "Numba Public Discussion - Public" group.
To unsubscribe from this group and stop receiving emails from it, send an email to numba-users...@continuum.io.
To view this discussion on the web visit https://groups.google.com/a/continuum.io/d/msgid/numba-users/f9464d69-d8f9-494d-b2fd-470a2ca4c694n%40continuum.io.