I think you are getting close. Application of the typemap simply requires
%apply (float* INPLACE_ARRAY1, int DIM1) {(float* data_location, int
unused)}
rather than the entire argument list.
Be sure you understand the use case. The (data_location, unused) pair is going
to be provided by a numpy array and its length. You might want to do a check
to make sure variable "unused" has the correct value before you pass the numpy
array data on to your function.
Typemaps are generally non-intuitive. But once you understand all the rules,
they start to make sense.
-Bill
On Nov 22, 2013, at 4:05 PM, Kaspar Emanuel wrote:
> Hi Bill,
>
> thanks for your response. So the function I am actually trying to wrap is:
>
> static inline void
> lilv_instance_connect_port(LilvInstance* instance,
> uint32_t port_index,
> void* data_location)
>
> It just passes on the pointer to the data_location (the audio buffer) and
> then you call lilv_instance_run(int nframes) where nframes could be the
> dimension of your buffer, or possibly less if you really want.
>
> So following your recommendations I tried to make a wrapper function:
>
> lilv_instance_pyconnect(LilvInstance* instance,
> uint32_t port_index,
> float* data_location, int unused)
>
> and then a typemap following what is in numpy.i :
>
>
> %typecheck(SWIG_TYPECHECK_DOUBLE_ARRAY,
> fragment="NumPy_Macros")
> (UNUSED1* UNUSED2, UNUSED3 UNUSED4, DATA_TYPE* INPLACE_ARRAY1, DIM_TYPE
> DIM1)
> {
> $1 = is_array($input) && PyArray_EquivTypenums(array_type($input),
> DATA_TYPECODE);
> }
> %typemap(in,
> fragment="NumPy_Fragments")
> (UNUSED1* UNUSED2, UNUSED3 UNUSED4, DATA_TYPE* INPLACE_ARRAY1, DIM_TYPE
> DIM1)
> (PyArrayObject* array=NULL, int i=1)
> {
> array = obj_to_array_no_conversion($input, DATA_TYPECODE);
> if (!array || !require_dimensions(array,1) || !require_contiguous(array)
> || !require_native(array)) SWIG_fail;
> $1 = (DATA_TYPE*) array_data(array);
> $2 = 1;
> for (i=0; i < array_numdims(array); ++i) $2 *= array_size(array,i);
> }
>
> which I tried to apply with:
>
>
> %apply (LilvInstance* instance, uint32_t port_index, float* INPLACE_ARRAY1,
> int DIM1) {(LilvInstance* instance, uint32_t port_index, float*
> data_location, int unused)}
>
> But it doesn’t seem to do anything an I just get a TypeError.
>
> You might have noticed I am a little bit out of my depth…
>
> Ta,
>
> Kaspar
>
>
>
> On 22 November 2013 22:40, Bill Spotz <[email protected]> wrote:
> Kaspar,
>
> Yes, in order for numpy.i typemaps to work, you need to provide dimensions.
> How is lilv_test(float*) supposed to know how large the float array is? Is
> it actually a method where the class knows the size? In cases where
> dimensions are not passed through the argument list, you have two options:
>
> 1. Write a proxy function that does have dimension arguments and calls the
> original function, and then wrap that instead of the original function.
>
> 2. Use the functions and macros in numpy.i to write new typemaps that work
> for your case.
>
> -Bill
>
> On Nov 22, 2013, at 3:30 PM, Kaspar Emanuel wrote:
>
> > Hey,
> > I am trying to improve the Lilv Python bindings to include numpy.i to allow
> > for creation and verification of audio test buffers using NumPy.
> >
> > I am just trying to get something working at the moment so I am tring to
> > wrap a test function.
> >
> > static inline void
> > lilv_test(float* data_location){}
> >
> > and I have in lilv.i:
> >
> > %apply (float* INPLACE_ARRAY1) {(float* data_location)};
> > This doesn’t produce any warnings or anything but when I try and use it
> > from Python I get:
> >
> > TypeError: in method 'lilv_test', argument 1 of type 'float *'
> > What does work is if I have:
> >
> > lilv_test(float* data_location, int n){}
> > and
> >
> > %apply (float* INPLACE_ARRAY1, int DIM1) {(float* data_location, int n)};
> > but this doesn’t fit very well with the functions I eventually want to
> > wrap, as they don’t have a dimension argument.
> >
> > Is it not possible to use INPLACE_ARRAY1 without a dimension?
> >
> > Thanks for any help,
> >
> > Kaspar
> >
> >
> > _______________________________________________
> > NumPy-Discussion mailing list
> > [email protected]
> > http://mail.scipy.org/mailman/listinfo/numpy-discussion
>
> ** Bill Spotz **
> ** Sandia National Laboratories Voice: (505)845-0170 **
> ** P.O. Box 5800 Fax: (505)284-0154 **
> ** Albuquerque, NM 87185-0370 Email: [email protected] **
>
>
>
>
>
> _______________________________________________
> NumPy-Discussion mailing list
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>
> _______________________________________________
> NumPy-Discussion mailing list
> [email protected]
> http://mail.scipy.org/mailman/listinfo/numpy-discussion
** Bill Spotz **
** Sandia National Laboratories Voice: (505)845-0170 **
** P.O. Box 5800 Fax: (505)284-0154 **
** Albuquerque, NM 87185-0370 Email: [email protected] **
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