Re: [Pyode-user] PyODE 0.1.4

[brett h. <bha...@ya...>]

Hi Tim,

Are you using ode-0.039, if so that is likely the cause of your build problem.
I've been making the wrappers around cvs from about 3 days ago.
http://sourceforge.net/cvs/?group_id=24884

The thin wrappers are just temporary, for building and testing.
To return python lists or tuples would be nice.  How do we do that?  I looked at some of your code
in the CVS and it seemed you were doing something like this already.

I aggree, the ode c++ wrappers are a pain in the ass; although they are good becuase they are a
standard part of osg.  Is there a way we can easily swap them out for your classes?  How should we
go about merging our code?  Maybe we can work with the ODE crew and make their c++ wrappers
better? 

Python's C interface looks too verbose for me.  Boost has made me lazy i think.  It could be
something to fall back on later.  I think we are close to having something working well with
boost, lets not give up on it now.

later,
-brett


--- Timothy Stranex <ti...@st...> wrote:
> Hey,
> 
> On Wed, 2004-03-24 at 06:21, brett hartshorn wrote:
> > get the new PyODE 0.1.4 here:
> > http://opart.org/pyode/
> 
> I get these errors when building:
> 
> $ scons
> scons: Reading SConscript files ...
> WARNING: ODE_ROOT env var not set!
> Defaulting to: /usr/local
> scons: done reading SConscript files.
> scons: Building targets ...
> g++ -Wall -ansi -fPIC -DNDEBUG -DBOOST_PYTHON_DYNAMIC_LIB
> -I/usr/include/python2.2 -I/usr/local/include -Iinclude -c -o
> PyODE/odecpp.os PyODE/odecpp.cpp
> PyODE/odecpp.cpp: In function `void pyODE::init_odecpp()':
> PyODE/odecpp.cpp:247: error: `setParam' is not a member of type `
>    dUniversalJoint'
> PyODE/odecpp.cpp:254: error: `getParam' is not a member of type `
>    dUniversalJoint'
> scons: *** [PyODE/odecpp.os] Error 1
> scons: building terminated because of errors.
> 
> > Tomorrow i will likey have completed doing all of the 'thin wrappers' for the get functions
> > returning a dReal.
> 
> Your 'thin wrappers' are just dereferencing dReal pointers but some
> methods like dBody's getPosition are returning an arrays of dReal, as
> far as I can tell. I'm guessing that these are just temporary to get it
> to build?
> 
> > Should we make our own vector and matrix classes and stick those into the thin wrappers,
> > or should we subclass all the classes from the ode c++ wrappers and overload them. Or
> > should we just scrap the ode c++ wrappers and make our own?
> 
> I think that whether we use the ODE C++ wrapper or write our own, we
> should write thin wrappers to convert vectors and matrices in simple
> Python lists. This will allow the user to choose whether they want to
> manipulate them using Numeric or their own vector and matrix classes.
> 
> I /feel/ that using the ODE's C++ interface is causing too much trouble
> and it would be easier to use its C API and wrap it so that it seems
> object-orientated to Python.
> 
> > and boost is very picky about things.
> 
> I played around with Python's C interface today. It is actually quite
> straightforward albeit verbose. It doesn't compare with Boost's elegance
> in the code but it has other advantages: the building system is simple
> and well-known by most Python users and dependency requirements (and the
> hassles that come with them) are reduced.
> 
> I'm unsure whether these advantages outweigh those of Boost, but I think
> we should consider it. I've attached a simple module using the C
> interface. You can build it by running 'python setup.py build'.
> 
> -- 
> Timothy Stranex <ti...@st...>
> http://www.stranex.com/~perspex/
> > #include <Python.h>
> 
> int isPrime(int num)
> {
>   int n, prime;
> 
>   prime = 1;
>   for (n=2; n < num; n++) {
>     if (num % n == 0) {
>       prime = 0;
>       break;
>     }
>   }
> 
>   return prime;
> }
> 
> static PyObject *nums_isPrime(PyObject *self, PyObject *args)
> {
>   int num;
> 
>   if (!PyArg_ParseTuple(args, "i", &num)) {
>     return NULL;
>   }
> 
>   return Py_BuildValue("i", isPrime(num));
> }
> 
> static PyObject *nums_factors(PyObject *self, PyObject *args)
> {
>   int num, i;
>   PyObject *list;
> 
>   if (!PyArg_ParseTuple(args, "i", &num)) {
>      return NULL;
>    }
> 
>    list = PyList_New(0);
>    if (!list) {
>      return NULL;
>    }
> 
>    for (i=1; i<=num; i++) {
>      if (num % i == 0) {
>        PyList_Append(list, Py_BuildValue("i", i));
>      }
>    }
> 
>    return list;
>  }
> 
>  static PyObject *nums_pfactors(PyObject *self, PyObject *args)
>  {
>    int num, i;
>    PyObject *f;
>    PyObject *pf;
>    PyObject *n;
> 
>    f = nums_factors(self, args);
>    if (!f) {
>      return NULL;
>    }
> 
>    pf = PyList_New(0);
>    for (i=0; i<PyList_Size(f); i++) {
>      n = PyList_GetItem(f, i);
>      if (isPrime((int) PyInt_AsLong(n))) {
>        PyList_Append(pf, n);
>      }
>    }
> 
>    Py_DECREF(f);
> 
>    return pf;
> }
> 
> void initnums(void)
> {
>   static PyMethodDef NumsMethods[] = {
>     {"isPrime", nums_isPrime, METH_VARARGS, "Check if an integer is prime."},
>     {"factors", nums_factors, METH_VARARGS, "Find the factors or an integer."},
>     {"pfactors", nums_pfactors, METH_VARARGS,
>      "Find the prime factors of an integer."},
>     {NULL, NULL, 0, NULL}
>   };
> 
>   (void) Py_InitModule("nums", NumsMethods);
> }
> > #!/usr/bin/env python
> 
> from distutils.core import setup, Extension
> 
> numsModule = Extension('nums', sources=['numsmodule.c'])
> 
> setup(name='Nums',
>       version='0.1',
>       description='Numbers',
>       ext_modules=[numsModule])
> 

> ATTACHMENT part 2 application/pgp-signature name=signature.asc



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