Defining and returning an array within a jitted function seems to be broken

[numba]

Defining and returning an array within a jitted function seems to be broken

[teoliphant]

Currently, you can't return array's from numba functions. Try passing the array in as an argument.

Also, we are deprecating the use of the "d" symbol. Use "f8" instead or "float64". You can also just try using @autojit which will detect types when it's called and compile an appropriate version.

-Travis

On Sep 27, 2012, at 12:59 PM, Hernan Grecco wrote:

While trying Numba for some simple operations I came to this:

import numpy as np

from numba import d, int_
from numba.decorators import jit as jit

@jit(ret_type=d[:], arg_types=[d[:], int_])
def calculate_moments(data, n_moments):

rs = data.shape[0]
result = np.zeros((n_moments, ))
for r in range(rs):
    for m in range(n_moments):
        result[m] += data[r] ** m

return result

data = np.random.random((1000,))
print(calculate_moments(data, 5))
output:

DEBUG -- translate:241:str_to_llvmtype
str_to_llvmtype(): str = ''
Traceback (most recent call last):
File "m1.py", line 9, in
@jit(ret_type=d[:], arg_types=[d[:], int_])
File "/Users/grecco/bin/anaconda/lib/python2.7/site-packages/numba/decorators.py", line 212, in jit
t.translate()
File "/Users/grecco/bin/anaconda/lib/python2.7/site-packages/numba/translate.py", line 951, in translate
getattr(self, 'op'+name)(i, op, arg)
File "/Users/grecco/bin/anaconda/lib/python2.7/site-packages/numba/translate.py", line 1544, in op_CALL_FUNCTION
func, args = self.func_resolve_type(func, args)
File "/Users/grecco/bin/anaconda/lib/python2.7/site-packages/numba/translate.py", line 1234, in func_resolve_type
lfunc = map_to_function(func.val, typs, self.mod)
File "/Users/grecco/bin/anaconda/lib/python2.7/site-packages/numba/translate.py", line 139, in map_to_function
typs = [str_to_llvmtype(x) if isinstance(x, str) else x for x in typs]
File "/Users/grecco/bin/anaconda/lib/python2.7/site-packages/numba/translate.py", line 246, in str_to_llvmtype
first_char = str[0]
IndexError: string index out of range
I think is related to have result as a np array. It is fine when I run the following (different purpose) code:

import numpy as np

from numba import d, int_
from numba.decorators import jit as jit

@jit(ret_type=d, arg_types=[d[:], int_])
def calculate_moment(data, moment):

rs = data.shape[0]
result = 0.0
for r in range(rs):
    result += data[r] ** moment

return result

data = np.random.random((1000,))
print(calculate_moment(data, 5))
Mac OS X 10.6.8
Python 2.7.3 AnacondaCE (default, Sep 4 2012, 10:42:42)
numba sha1: 948c5b9

Ps.- After writing this, I realized that in the fbcorr example you give the output array

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[hgrecco]

Passing the argument as an array did the job. And autojit worked perfectly. Thanks