问题
I'm trying to call a @guvectorize
inside a @guvectorize
but I have an error saying :
Untyped global name 'regNL_nb': cannot determine Numba type of <class 'numpy.ufunc'>
File "di.py", line 12:
def H2Delay_nb(S1, S2, R2):
H1 = regNL_nb(S1, S2)
^
here is an MRE:
import numpy as np
from numba import guvectorize, float64, int64, njit, cuda, jit
@guvectorize(["float64[:], float64[:], float64[:]"], '(n),(n)->(n)')
def regNL_nb(S1, S2, h2):
for i in range(len(S1)):
h2[i] = S1[i] + S2[i]
@guvectorize(["float64[:], float64[:], float64[:]"], '(n),(n)->(n)',nopython=True)
def H2Delay_nb(S1, S2, R2):
H1 = regNL_nb(S1, S2)
H2 = regNL_nb(S1, S2,)
for i in range(len(S1)):
R2[i] = H1[i] + H2[i]
S1 = np.array([1,2,3,4,5,6,7,8,9])
S2 = np.array([1,2,3,4,5,6,7,8,9])
H2 = H2Delay_nb(S1, S2)
print(H2)
I don't know how do I tell to numba that the function regNL_nb is a guvectorize function.
回答1:
My answer is only for the case if you're fine with replacing @guvectorize with @njit, it will be totally same code, same fast, just a bit more longer syntax to use.
It is probably some issue with accepting @guvectorize
-ed functions inside other guvectorized function in nopython mode.
But Numba accepts perfectly good just regular @njit
-ed functions inside other njited. So you may rewrite your function to use @njit, your function signature will remain same as @guvectorize-ed for outside world. @njit version will just need extra usage of np.empty_like(...)
+ return inside function.
To remind you - all @njit-ed functions are always having nopython mode enabled, so your njited code will be same fast as guvectorize+nopython.
Also I provide CUDA solution as second code snippet.
You may also make @njited only internal helper function, but external you probably can still have as @guvectorize-ed. Also if you want universal function (accepting any inputs) just remove signature 'f8[:](f8[:], f8[:])'
from njited definition, signature will be auto-resolved on call.
Final code looks like this:
Try it online!
import numpy as np
from numba import guvectorize, float64, int64, njit, cuda, jit
@njit('f8[:](f8[:], f8[:])', cache = True)
def regNL_nb(S1, S2):
h2 = np.empty_like(S1)
for i in range(len(S1)):
h2[i] = S1[i] + S2[i]
return h2
@njit('f8[:](f8[:], f8[:])', cache = True)
def H2Delay_nb(S1, S2):
H1 = regNL_nb(S1, S2)
H2 = regNL_nb(S1, S2)
R2 = np.empty_like(H1)
for i in range(len(S1)):
R2[i] = H1[i] + H2[i]
return R2
S1 = np.array([1,2,3,4,5,6,7,8,9], dtype = np.float64)
S2 = np.array([1,2,3,4,5,6,7,8,9], dtype = np.float64)
H2 = H2Delay_nb(S1, S2)
print(H2)
Output:
[ 4. 8. 12. 16. 20. 24. 28. 32. 36.]
CUDA variant of same code, it needs extra functions-wrappers if you want to automatically create and return resulting array, because CUDA-code function doesn't allow to have return value:
import numpy as np
from numba import guvectorize, float64, int64, njit, cuda, jit
@cuda.jit('void(f8[:], f8[:], f8[:])', cache = True)
def regNL_nb_cu(S1, S2, h2):
for i in range(len(S1)):
h2[i] = S1[i] + S2[i]
@njit('f8[:](f8[:], f8[:])', cache = True)
def regNL_nb(S1, S2):
h2 = np.empty_like(S1)
regNL_nb_cu(S1, S2, h2)
return h2
@cuda.jit('void(f8[:], f8[:], f8[:])', cache = True)
def H2Delay_nb_cu(S1, S2, R2):
H1 = regNL_nb(S1, S2)
H2 = regNL_nb(S1, S2)
for i in range(len(S1)):
R2[i] = H1[i] + H2[i]
@njit('f8[:](f8[:], f8[:])', cache = True)
def H2Delay_nb(S1, S2):
R2 = np.empty_like(S1)
H2Delay_nb_cu(S1, S2, R2)
return R2
S1 = np.array([1,2,3,4,5,6,7,8,9], dtype = np.float64)
S2 = np.array([1,2,3,4,5,6,7,8,9], dtype = np.float64)
H2 = H2Delay_nb(S1, S2)
print(H2)
回答2:
@guvectorize(["float64[:], float64[:], float64[:]"], '(n),(n)->(n)',nopython=True)
def H2Delay_nb(S1, S2, R2):
H1 = regNL_nb(S1, S2)
H2 = regNL_nb(S1, S2,)
for i in range(len(S1)):
R2[i] = H1[i] + H2[i]
By using the parameter nopython = True
you deactivate the object mode and hence Numba isn't able to handle all values as Python objects (refer to: https://numba.pydata.org/numba-doc/latest/glossary.html#term-object-mode)
In general are Panda, Numba or other function calls not possible if you use nopython = True
. There is only a limited amount of libraries you can use with Numba Jit (in nopython
).
The full list can be found here: https://numba.pydata.org/numba-doc/dev/reference/numpysupported.html.
So what you are trying to do isn't possible, except of disabling nopython
, that is:
@guvectorize(["float64[:], float64[:], float64[:]"], '(n),(n)->(n)',nopython=False)
def H2Delay_nb(S1, S2, R2):
H1 = regNL_nb(S1, S2)
H2 = regNL_nb(S1, S2,)
for i in range(len(S1)):
R2[i] = H1[i] + H2[i]
Going with this approach the programme outputs the correct value, i.e. [ 4. 8. 12. 16. 20. 24. 28. 32. 36.]
for H2
.
I also found another StackOverflow question dealing with a familiar issue: numba - TypingError: cannot determine Numba type of <class 'builtin_function_or_method'>. Credits where credit is due: Kevin K. suggested in the mentioned thread that you shall use 'simpler' data types - which are most often found in CPython. Other than that, and I fully agree with him on this point, I wouldn't be aware of any possible solution in nopython
mode activated.
Sources:
- numba - TypingError: cannot determine Numba type of <class 'builtin_function_or_method'>
- https://numba.pydata.org/numba-doc/latest/glossary.html
- https://numba.pydata.org/numba-doc/latest/proposals/type-inference.html
- https://numba.pydata.org/numba-doc/dev/reference/numpysupported.html
- https://github.com/numba/numba/issues/4627
来源:https://stackoverflow.com/questions/65353407/how-call-a-guvectorize-inside-a-guvectorize-in-numba