numpy-discussion

[Numpy-discussion] how to get info about internals of an array object ?

[Sebastian H. <ha...@ms...>]

Hi,
what I'm asking is if numpy has an equivalent to numarray's info() function:
>>> na.arange(10).info()
class: <class 'numarray.numarraycore.NumArray'>
shape: (10,)
strides: (4,)
byteoffset: 0
bytestride: 4
itemsize: 4
aligned: 1
contiguous: 1
buffer: <memory at 0x085b7ec8 with size:0x00000028 held by object 0x4306e5e0 
aliasing object 0x00000000>
data pointer: 0x085b7ec8 (DEBUG ONLY)
byteorder: 'little'
byteswap: 0
type: Int32

This was always helpful to me when debugging C binding code.

Especially I'm asking if there is any way to get the memory address of an 
array - for debugging purposes only - of course ;-)

Thanks,
Sebastian Haase

Re: [Numpy-discussion] how to get info about internals of an array object ?

[Francesc A. <fa...@ca...>]

El dj 14 de 09 del 2006 a les 18:20 -0700, en/na Sebastian Haase va
escriure:

> Especially I'm asking if there is any way to get the memory address of an=
=20
> array - for debugging purposes only - of course ;-)

For this, you can print the data buffer:

In [1]:import numpy
In [2]:a=3Dnumpy.array([1])
In [3]:a.data
Out[3]:<read-write buffer for 0x82a9970, ptr 0x821f630, size 4 at
0xb6dd3300>

although I'm not sure which number is the memory address I'd say it's
the last one.

Cheers,

--=20
>0,0<   Francesc Altet     http://www.carabos.com/
V   V   C=C3=A1rabos Coop. V.   Enjoy Data
 "-"

Re: [Numpy-discussion] how to get info about internals of an arrayobject ?

[Albert S. <fu...@gm...>]

> -----Original Message-----
> From: num...@li... [mailto:numpy-
> dis...@li...] On Behalf Of Sebastian Haase
> Sent: 15 September 2006 03:21
> To: numpy-discussion
> Subject: [Numpy-discussion] how to get info about internals of an
> arrayobject ?
> 
> Hi,
> what I'm asking is if numpy has an equivalent to numarray's info()
> function:

> <snip>

> This was always helpful to me when debugging C binding code.
> 
> Especially I'm asking if there is any way to get the memory address of an
> array - for debugging purposes only - of course ;-)

numpy.array([]).__array_interface__['data'][0]

Cheers,

Albert

Re: [Numpy-discussion] how to get info about internals of an arrayobject ?

[Travis O. <oli...@ie...>]

Albert Strasheim wrote:
>> -----Original Message-----
>> From: num...@li... [mailto:numpy-
>> dis...@li...] On Behalf Of Sebastian Haase
>> Sent: 15 September 2006 03:21
>> To: numpy-discussion
>> Subject: [Numpy-discussion] how to get info about internals of an
>> arrayobject ?
>>
>> Hi,
>> what I'm asking is if numpy has an equivalent to numarray's info()
>> function:
>>     
>
>   
>> <snip>
>>     
>
>   
>> This was always helpful to me when debugging C binding code.
>>
>> Especially I'm asking if there is any way to get the memory address of an
>> array - for debugging purposes only - of course ;-)
>>     
>
> numpy.array([]).__array_interface__['data'][0]
>   

Or

numpy.ctypes._as_parameter_

(should work even if you don't have ctypes installed)

-Travis

Re: [Numpy-discussion] how to get info about internals of an array object ?

[Travis O. <oli...@ie...>]

Sebastian Haase wrote:
> Hi,
> what I'm asking is if numpy has an equivalent to numarray's info() function:
>   
>>>> na.arange(10).info()
>>>>         
numpy.numarray.info(numpy.arange(10))

(get recent SVN as there were some bugs just fixed.

-Travis

Re: [Numpy-discussion] how to get info about internals of an array object ?

[Sebastian H. <ha...@ms...>]

On Friday 15 September 2006 10:00, Travis Oliphant wrote:
> Sebastian Haase wrote:
> > Hi,
> >
> > what I'm asking is if numpy has an equivalent to numarray's info() 
function:
> >>>> na.arange(10).info()
>
> numpy.numarray.info(numpy.arange(10))
>
> (get recent SVN as there were some bugs just fixed.
>
> -Travis

Thanks,

should this maybe also be added somewhere in the numpy module itself !?
I guess the question is, what the original intent was for numarray to put it 
in (only for debugging ?) -- then we could decide if this would also make 
sense for numpy.

I have never used numpy.info(obj) - I don't know what is does (compared to 
__doc__)   but maybe it could be extended like
if isinstance( obj , N.ndarray):
    print  N.numarray.info( obj )

right now it prints nothings (and returns None)

Thanks,
Sebastian Haase

Re: [Numpy-discussion] how to get info about internals of an array object ?

[Travis O. <oli...@ee...>]

Sebastian Haase wrote:

>On Friday 15 September 2006 10:00, Travis Oliphant wrote:
>  
>
>>Sebastian Haase wrote:
>>    
>>
>>>Hi,
>>>
>>>what I'm asking is if numpy has an equivalent to numarray's info() 
>>>      
>>>
>function:
>  
>
>>>>>>na.arange(10).info()
>>>>>>            
>>>>>>
>>numpy.numarray.info(numpy.arange(10))
>>
>>(get recent SVN as there were some bugs just fixed.
>>
>>-Travis
>>    
>>
>
>Thanks,
>
>should this maybe also be added somewhere in the numpy module itself !?
>I guess the question is, what the original intent was for numarray to put it 
>in (only for debugging ?) -- then we could decide if this would also make 
>sense for numpy.
>
>I have never used numpy.info(obj) - I don't know what is does (compared to 
>__doc__)   
>
It prints the doc string of an object searching for it better than help 
seems to do and without a "pager".

Compare numpy.info(numpy.sin) versus help(numpy.sin)

I don't know what the info method was for other than debugging.  

What about having the __doc__ attribute of an ndarray return the info?


-Travis

Re: [Numpy-discussion] how to get info about internals of an array object ?

[Sebastian H. <ha...@ms...>]

On Friday 15 September 2006 12:49, Travis Oliphant wrote:
> Sebastian Haase wrote:
> >On Friday 15 September 2006 10:00, Travis Oliphant wrote:
> >>Sebastian Haase wrote:
> >>>Hi,
> >>>
> >>>what I'm asking is if numpy has an equivalent to numarray's info()
> >
> >function:
> >>>>>>na.arange(10).info()
> >>
> >>numpy.numarray.info(numpy.arange(10))
> >>
> >>(get recent SVN as there were some bugs just fixed.
> >>
> >>-Travis
> >
> >Thanks,
> >
> >should this maybe also be added somewhere in the numpy module itself !?
> >I guess the question is, what the original intent was for numarray to put
> > it in (only for debugging ?) -- then we could decide if this would also
> > make sense for numpy.
> >
> >I have never used numpy.info(obj) - I don't know what is does (compared to
> >__doc__)
>
> It prints the doc string of an object searching for it better than help
> seems to do and without a "pager".
>
> Compare numpy.info(numpy.sin) versus help(numpy.sin)
In PyShell I would miss the output of numpy.info(numpy.sin) since it goes to 
the (C) stdout and not to the (sometimes redirected ) python sys.stdout.
So it seems it prints N.sin.__doc__

The output from help(...) goes to the (python) sys.stdout (or stderr !?)  and 
is quite long (and mostly just generec info about ufuncs ...)

>
> I don't know what the info method was for other than debugging.
>
> What about having the __doc__ attribute of an ndarray return the info?
>
Maybe,
but honestly I would *not* expect any kind of "live inspection" to be done by 
__doc__
I would expect more like 
"ndarray is an efficient way to handle large data sets in python - it is the 
bases for Numerical Python, see www.scipy.org "

Maybe info() should just be an array attribute - just like it was it numarray.

-Sebastian