[Numpy-discussion] ndarray of object dtype

Ioan Ferencik ioan.ferencik@tkk...
Fri Oct 8 02:18:06 CDT 2010


thanks,
it was actually obvious and I figured it out minutes later I sent the message.
Thanks anyway.




Quoting Robert Kern <robert.kern@gmail.com>:

> On Thu, Oct 7, 2010 at 10:09, Ioan Ferencik <ioan.ferencik@tkk.fi> wrote:
>> Hello Robert,
>>
>> I dare to bother you again with some  questions.
>>
>> this time I have a numpy array with fields
>> ar = array([(1.0, 2.0, 3, 4), (2.0, 3.0, 4, 5)], dtype={'names':
>> ['q','wl','cssid','br'], 'formats':['f4', 'f4', 'i4', 'i4'],
>> 'offsets': [0, 4, 8, 12]}, order='F')
>>
>> on C API I want to match this struct
>> typedef struct val1{
>>        float q;
>>        float wl;
>>        int cssid;
>>        int br;
>> }hm1dval1;
>>
>> to an element of this array
>> I get the array object, i can see the fields. The type of the array
>> elements is Pyarray_VOID
>>
>> however following code gives me a segfault
>>
>> hm1dval1 **s = PyArray_DATA(ao);
>
> Since this is *not* an object array but an array of hm1dval1 structs,
> you declare it like so:
>
> hm1dval1 *s = PyArray_DATA(ao);
>
> --
> Robert Kern
>
> "I have come to believe that the whole world is an enigma, a harmless
> enigma that is made terrible by our own mad attempt to interpret it as
> though it had an underlying truth."
>   -- Umberto Eco
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Ioan Ferencik
PhD student
Aalto University
School of Science and Technology
Faculty Of Civil and Env. Engineering
Lahti Center
Tel: +358505122707




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