python之'值错误 : Nothing can be done for the type class 'numpy.core.records.recarray' > at the moment' error

我正在尝试运行一个简单的线性回归(使用 Python 中的 rpy2)，但在运行以下脚本时遇到了措辞奇怪的错误:

from numpy import array, rec 
from numpy.random import normal as nprandom 
from rpy2.robjects import numpy2ri, r 
 
foo = array(range(10)) 
bar = foo + nprandom(0,1,10) 
 
d = rec.fromarrays([foo, bar], names=('foo','bar')) 
fit = r.lm('bar ~ foo', data=d) 
print fit.rx2('coefficients') 

这是控制台输出:

>>> from numpy import array, rec 
>>> from numpy.random import normal as nprandom 
>>> from rpy2.robjects import numpy2ri, r 
>>>  
>>> foo = array(range(10)) 
>>> bar = foo + nprandom(0,1,10) 
>>>  
>>> d = rec.fromarrays([foo, bar], names=('foo','bar')) 
>>> fit = r.lm('bar ~ foo', data=d) 
Traceback (most recent call last): 
  File "<stdin>", line 1, in <module> 
  File "/usr/local/lib/python2.6/dist-packages/rpy2/robjects/functions.py", line 82, in __call__ 
    return super(SignatureTranslatedFunction, self).__call__(*args, **kwargs) 
  File "/usr/local/lib/python2.6/dist-packages/rpy2/robjects/functions.py", line 33, in __call__ 
    new_kwargs[k] = conversion.py2ri(v) 
  File "/usr/local/lib/python2.6/dist-packages/rpy2/robjects/__init__.py", line 134, in default_py2ri 
    raise(ValueError("Nothing can be done for the type %s at the moment." %(type(o)))) 
ValueError: Nothing can be done for the type <class 'numpy.core.records.recarray'> at the moment. 
>>> print fit.rx2('coefficients') 

我正在运行 Python 2.6.5 并且有 numpy 版本 1.6.1

有谁知道是什么导致了这个错误？

请您参考如下方法:

你需要添加:

rpy2.robjects.activate() 

在导入 numpy2ri 之后。 This SO post引用 rpy2 文档:

That import alone is sufficient to switch an automatic conversion of numpy objects into rpy2 objects.

Why make this an optional import, while it could have been included in the function py2ri() (as done in the original patch submitted for that function) ?

Although both are valid and reasonable options, the design decision was taken in order to decouple rpy2 from numpy the most, and do not assume that having numpy installed automatically meant that a programmer wanted to use it.

希望这能解决您的问题。