Centre Blaise Pascal » Bench4GPU

/*  Example of change values in array in the Numpy-C-API. */

/* http://scipy-lectures.github.io/advanced/interfacing_with_c/interfacing_with_c.html */

/* http://dsnra.jpl.nasa.gov/software/Python/numpydoc/numpy-13.html */

/* http://enzo.googlecode.com/.../Grid_ConvertToNumpy.C */

/* http://docs.scipy.org/doc/numpy/reference/c-api.array.html#data-access */

/* 

   What is absolutely necessary to know:

   - 

*/

#include <Python.h>

#include <numpy/arrayobject.h>

#include <math.h>

#include <stdio.h>

#include <sys/time.h>

/* All RNG numbers of Marsaglia are Unsigned int32 ! */

#define znew  ((z=36969*(z&65535)+(z>>16))<<16)

#define wnew  ((w=18000*(w&65535)+(w>>16))&65535)

#define MWC   (znew+wnew)

#define SHR3  (jsr=(jsr=(jsr=jsr^(jsr<<17))^(jsr>>13))^(jsr<<5))

#define CONG  (jcong=69069*jcong+1234567)

#define KISS  ((MWC^CONG)+SHR3)

#define LFIB4 (t[c]=t[c]+t[c+58]+t[c+119]+t[++c+178])

#define SWB   (t[c+237]=(x=t[c+15])-(y=t[++c]+(x<y)))

#define UNI   (KISS*2.328306e-10)

#define VNI   ((long) KISS)*4.656613e-10

#define MWCfp (float)MWC * 2.328306435454494e-10f

#define KISSfp (float)KISS * 2.328306435454494e-10f

#define SHR3fp (float)SHR3 * 2.328306435454494e-10f

// static PyObject* array_metropolis_np(PyObject* self, PyObject *args)

static PyObject* array_metropolis_np(PyObject* self, PyObject *args)

{

  PyObject *in_array;

  PyArrayObject *local;

  unsigned int z,w;

  long iterations=1;

  int seed_w=521288629,seed_z=362436069,jcong=380116160,jsr=123456789;

  int factor;

  float B=0,J=0,T=0;

  double elapsed=0;

  unsigned long i;

  struct timeval tv1,tv2;

  struct timezone tz;

  /*  parse single numpy array argument */

  /* http://docs.python.org/release/1.5.2p2/ext/parseTuple.html */

  /* O for in_array */

  /* fff  for 3 float values (Coupling, Magnetic Field, Temperature)*/

  /* l for 1 long int value (iterations) */

  /* ii for 2 int values (2 seeds) */

  if (!PyArg_ParseTuple(args, "Offflii", &in_array,

                        &J,&B,&T,&iterations,&seed_w,&seed_z))

    {

      printf("Not null argument provided !\n");

      return NULL;

    }

  /* display the extra parameters */

  printf("Parameters for physics: J=%f\nB=%f\nT=%f\n",J,B,T);

  printf("Parameters for simulation: iterations=%ld\nseed_w=%i\nseed_z=%i\n",

         iterations,seed_w,seed_z);

  local = (PyArrayObject *) PyArray_ContiguousFromAny(in_array, NPY_INT32, 2, 2);

  if (PyArray_NDIM(local)!=2) {

    printf("This simulation is only for 2D arrays !\n");

    return NULL;

  }

  npy_intp size_x=*(npy_intp *)(PyArray_DIMS(local));

  npy_intp size_y=*(npy_intp *)(PyArray_DIMS(local)+1);

  /* Cast necessary, PyArg_ParseTuple() does not support any unsigned type ! */

  w=(unsigned int)seed_w;

  z=(unsigned int)seed_z;

  gettimeofday(&tv1, &tz);

  printf("Simulation started: ...");

  for (i=0;i<(unsigned long)iterations;i++) {

    npy_intp x=MWC%size_x ;

    npy_intp y=MWC%size_y ;

    int p=*(int *)PyArray_GETPTR2(local,x,y);

    int d=*(int *)PyArray_GETPTR2(local,x,(y+1)%size_y);

    int u=*(int *)PyArray_GETPTR2(local,x,(y-1)%size_y);

    int l=*(int *)PyArray_GETPTR2(local,(x-1)%size_x,y);

    int r=*(int *)PyArray_GETPTR2(local,(x+1)%size_x,y);

    float DeltaE=J*(float)p*(2.*(float)(u+d+l+r)+B);

    factor=((DeltaE < 0.0f) || (MWCfp < exp(-DeltaE/T))) ? -1:1;

    *(int *)PyArray_GETPTR2(local,x,y)=(factor*p);

  }

  gettimeofday(&tv2, &tz);    

  elapsed=(double)((tv2.tv_sec-tv1.tv_sec) * 1000000L +        \

                   (tv2.tv_usec-tv1.tv_usec))/1000000.; 

  printf("done in %.2f seconds !\n",elapsed);

  return PyArray_Return(local);

}

static PyObject* array_display_np(PyObject* self, PyObject *args)

{

  PyObject *in_array;

  PyArrayObject      *local;

  unsigned int i,x,y;

  /*  parse single numpy array argument */

  /* http://docs.python.org/release/1.5.2p2/ext/parseTuple.html */

  /* O for in_array */

  if (!PyArg_ParseTuple(args, "O", &in_array)) {

    printf("Not null argument provided !\n");

    return NULL;

  }

  local = (PyArrayObject *) PyArray_ContiguousFromObject(in_array, PyArray_NOTYPE, 2, 2);

  /* display the size of array */

  printf("Array has %i dimension(s) : size of ",PyArray_NDIM(local));

  if (PyArray_NDIM(local)==1) {

      printf("%i\n",(int)*(PyArray_DIMS(local)));

  }

  else {

    for (i=0;i<PyArray_NDIM(local)-1;i++) {

      printf("%ix",(int)*(PyArray_DIMS(local)+i));

    }

    printf("%i\n",(int)*(PyArray_DIMS(local)+PyArray_NDIM(local)-1));

  }

  /* display the array */

  printf("[");

  for (x=0;x<(unsigned int)(int)*(PyArray_DIMS(local));x++) {

    printf("[");

    for (y=0;y<(unsigned int)(int)*(PyArray_DIMS(local)+1);y++)

      printf("%2i ",* (int *)PyArray_GETPTR2(local,x,y));

    printf("]\n ");

  }

  printf("]\n");

  // Py_INCREF(local);

  /*  construct the output array, like the input array */

  return PyArray_Return(local);

}

/*  define functions in module */

static PyMethodDef ArrayMethods[] =

{

     {"array_metropolis_np", array_metropolis_np, METH_VARARGS,

         "evaluate a metropolis simulation on a numpy array"},

     {"array_display_np", array_display_np, METH_VARARGS,

         "evaluate a metropolis simulation on a numpy array"},

     {NULL, NULL, 0, NULL}

};

/* module initialization */

PyMODINIT_FUNC

initarray_module_np(void)

{

     (void) Py_InitModule("array_module_np", ArrayMethods);

     /* IMPORTANT: this must be called */

     import_array();

}