naive_synthesis.c

基于java的3d开发库。对坐java3d的朋友有很大的帮助。

*/
/************************************************************************/
/*
   bw - bandwidth
   m - order
   data - a pointer to double array of size (2*bw) containing a synthesized
          function.  
   result - a pointer to double array of size (bw-m) and containing the
            computed Legendre coefficients, starting with the Pmm
	    coefficient.
   workspace - a pointer to double array of size (32*bw)

   timing - 1 to turn on timing info

   runtime - a double slot for writing time

   loops - number of timing loops

*/


void Naive_Analysis_Timing(double *data,
			   int bw,
			   int m,
			   double *result, 
			   int timing,
			   double *runtime,
			   int loops,
			   double *workspace)
{
    double *prev, *prevprev, *temp1, *temp2, *temp3, *temp4, *x_i, *eval_args;
    double *wdata;
    const double *weight_vec;
    int i, j, l;

    double total_time, tstart = 0.0, tstop;

    prevprev = workspace;
    prev = prevprev + (2*bw);
    temp1 = prev + (2*bw);
    temp2 = temp1 + (2*bw);
    temp3 = temp2 + (2*bw);
    temp4 = temp3 + (2*bw);
    x_i = temp4 + (2*bw);
    eval_args = x_i + (2*bw);
    wdata = eval_args + (2*bw);


    /* get the evaluation nodes */
    ns_EvalPts(2*bw,x_i);
    ns_ArcCosEvalPts(2*bw,eval_args);
    


  /* start the timer
    if (timing)
      gettimeofday(&ftstart,0); */
    if (timing)
      tstart = csecond();

  /* main timing loop */
  for (l=0; l< loops; l++)
    {
      /* set initial values of first two Pmls */
      for (i=0; i<2*bw; i++) 
	prevprev[i] = 0.0;
      if (m == 0) {
	for (i=0; i<2*bw; i++) {
	  prev[i] = 0.5;
	}
      }
      else 
	ns_Pmm_L2(m, eval_args, 2*bw, prev);

      /* make sure result is zeroed out */
      for (i=0; i<(bw-m); i++)
	result[i] = 0.0;

      /* apply quadrature weights */
      weight_vec = get_weights(bw);

      for (i=0; i<(2*bw); i++)
	wdata[i] = data[i] * weight_vec[i];

      /* compute Pmm coefficient */

      for (j=0; j<(2*bw); j++)
	  result[0] += wdata[j] * prev[j];

      /* now generate remaining pmls while computing coefficients */

      for (i=0; i<bw-m-1; i++) {
	ns_vec_mul(ns_L2_cn(m,m+i),prevprev,temp1,2*bw);
	ns_vec_pt_mul(prev, x_i, temp2, 2*bw);
	ns_vec_mul(ns_L2_an(m,m+i), temp2, temp3, 2*bw);
	ns_vec_add(temp3, temp1, temp4, 2*bw); /* temp4 now contains P(m,m+i+1) */
	
	/* compute this coefficient */
	for (j=0; j<(2*bw); j++)
	  result[i+1] += wdata[j] * temp4[j];

	/* now update Pi and P(i+1) */

	memcpy(prevprev, prev, sizeof(double) * 2 * bw);
	memcpy(prev, temp4, sizeof(double) * 2 * bw);

      }
    } /* closes main timing loop */

  if (timing)
    {

      tstop = csecond();
      total_time = tstop - tstart;
      *runtime = total_time;

      fprintf(stdout,"\n");
      fprintf(stdout,"Program: Naive Legendre Transform \n");
      fprintf(stdout,"m = %d\n", m);
      fprintf(stdout,"Bandwidth = %d\n", bw);
#ifndef WALLCLOCK
      fprintf(stdout,"Total elapsed cpu time: %f seconds.\n\n", total_time); 
#else
      fprintf(stdout,"Total elapsed wall time: %f seconds.\n\n", total_time); 
#endif

    }
  else
    *runtime = 0.0;
}



/************************************************************************/
/*
   bw - bandwidth
   m - order
   data - a pointer to double array of size (2*bw) containing a synthesized
          function.  
   result - a pointer to double array of size (bw-m) and containing the
            computed Legendre coefficients, starting with the Pmm
	    coefficient.
   workspace - a pointer to double array of size (32*bw)

   timing - 1 to turn on timing info

   runtime - a double slot for writing time

   loops - number of timing loops


   Just like the above routine EXCEPT I precompute the
   legendre functions before turning on the stopwatch.

*/


void Naive_Analysis_TimingX(double *data,
			    int bw,
			    int m,
			    double *result, 
			    int timing,
			    double *runtime,
			    int loops,
			    double *workspace)
{
  double *prev, *prevprev, *temp1, *temp2, *temp3, *temp4, *x_i, *eval_args;
  double *wdata;
  const double *weight_vec;
  int i, j, l;
  
  double *storeplm, *storeplm_ptr;
  double result0, result1, result2, result3;

  double total_time, tstart = 0, tstop;
  
  prevprev = workspace;
  prev = prevprev + (2*bw);
  temp1 = prev + (2*bw);
  temp2 = temp1 + (2*bw);
  temp3 = temp2 + (2*bw);
  temp4 = temp3 + (2*bw);
  x_i = temp4 + (2*bw);
  eval_args = x_i + (2*bw);
  wdata = eval_args + (2*bw);
  
  storeplm = (double *) malloc(sizeof(double) * 2 * bw *
			       (bw - m));

  storeplm_ptr = storeplm;

  /* get the evaluation nodes */
  ns_EvalPts(2*bw,x_i);
  ns_ArcCosEvalPts(2*bw,eval_args);
  
  /* set initial values of first two Pmls */
  for (i=0; i<2*bw; i++) 
    prevprev[i] = 0.0;
  if (m == 0)
    for (i=0; i<2*bw; i++)
      prev[i] = 0.5;
  else 
    ns_Pmm_L2(m, eval_args, 2*bw, prev);

  memcpy(storeplm, prev, (size_t) sizeof(double) * 2 * bw);

  for(i = 0; i < bw - m - 1; i++)
    {
      ns_vec_mul(ns_L2_cn(m,m+i),prevprev,temp1,2*bw);
      ns_vec_pt_mul(prev, x_i, temp2, 2*bw);
      ns_vec_mul(ns_L2_an(m,m+i), temp2, temp3, 2*bw);
      ns_vec_add(temp3, temp1, temp4, 2*bw); /* temp4 now contains P(m,m+i+1) */
      
      storeplm += (2 * bw);
      memcpy(storeplm, temp4, (size_t) sizeof(double) * 2 * bw);
      memcpy(prevprev, prev, (size_t) sizeof(double) * 2 * bw);
      memcpy(prev, temp4, (size_t) sizeof(double) * 2 * bw);
    }

  storeplm = storeplm_ptr;

  /* start the timer */
  if (timing)
    tstart = csecond();
  
  /* main timing loop */
  for (l=0; l< loops; l++)
    {
      
      /* make sure result is zeroed out */
      for (i=0; i<(bw-m); i++)
	result[i] = 0.0;
      
      /* apply quadrature weights */
      weight_vec = get_weights(bw);
      
      ns_vec_pt_mul(data, weight_vec, wdata, 2 * bw);
      
      storeplm = storeplm_ptr;

      for (i = 0; i < bw - m; i++)
	{
	  result0 = 0.0; result1 = 0.0;
	  result2 = 0.0; result3 = 0.0;

	  for(j = 0; j < (2 * bw) % 4; ++j)
	    result0 += wdata[j] * storeplm[j];
	  for( ; j < (2 * bw); j += 4)
	    {
	      result0 += wdata[j] * storeplm[j];
	      result1 += wdata[j + 1] * storeplm[j + 1];
	      result2 += wdata[j + 2] * storeplm[j + 2];
	      result3 += wdata[j + 3] * storeplm[j + 3];
	    }
	  result[i] = result0 + result1 + result2 + result3;

	  storeplm += (2 * bw);
	}

    } /* closes main timing loop */
  
  if (timing)
    {
      
      tstop = csecond();
      total_time = tstop - tstart;
      *runtime = total_time;
      
      fprintf(stdout,"\n");
      fprintf(stdout,"Program: Naive Legendre Transform \n");
      fprintf(stdout,"m = %d\n", m);
      fprintf(stdout,"Bandwidth = %d\n", bw);
#ifndef WALLCLOCK
      fprintf(stdout,"Total elapsed cpu time: %f seconds.\n\n", total_time); 
#else
      fprintf(stdout,"Total elapsed wall time: %f seconds.\n\n", total_time); 
#endif

    }
  else
    *runtime = 0.0;

  storeplm = storeplm_ptr;

  free(storeplm);
}





/************************************************************************/
/*
   bw - bandwidth
   m - order
   data - a pointer to double array of size (2*bw) containing a synthesized
          function.
   plmtable - a pointer to a double array of size (2*bw*(bw-m));
	      contains the precomputed plms

   result - a pointer to double array of size (bw-m) and containing the
            computed Legendre coefficients, starting with the Pmm
	    coefficient.

   workspace - array of size 2 * bw;

   A minimal, hacked version of the above routine, except that
   as input ones of the arguments is the precomputed table of
   necessary associated Legendre functions.

*/


void Naive_AnalysisX(double *data,
		     int bw,
		     int m,
		     double *result,
		     double *plmtable,
		     double *workspace)
{
  int i, j;
  const double *weight_vec;
  double result0, result1, result2, result3;
  register double *wdata;

  wdata = workspace;

  /* make sure result is zeroed out */
  for (i=0; i<(bw-m); i++)
    result[i] = 0.0;



  /* apply quadrature weights */
  weight_vec = get_weights(bw);
      
  /*  ns_vec_pt_mul(data, weight_vec, wdata, 2 * bw); */

  for(i = 0; i < 2 * bw; i++)
    wdata[i] = data[i] * weight_vec[i];

  for (i = 0; i < bw - m; i++)
	{
	  result0 = 0.0; result1 = 0.0;
	  result2 = 0.0; result3 = 0.0;
	  
	  for(j = 0; j < (2 * bw) % 4; ++j)
	    result0 += wdata[j] * plmtable[j];
	  for( ; j < (2 * bw); j += 4)
	    {
	      result0 += wdata[j] * plmtable[j];
	      result1 += wdata[j + 1] * plmtable[j + 1];
	      result2 += wdata[j + 2] * plmtable[j + 2];
	      result3 += wdata[j + 3] * plmtable[j + 3];
	    }
	  result[i] = result0 + result1 + result2 + result3;

	  plmtable += (2 * bw);
	}

}


/************************************************************************/
/* This is the procedure that synthesizes a function from a list
   of coefficients of a Legendre series.  Function is synthesized
   at the (2*bw) Chebyshev nodes. Associated Legendre functions are
   assumed to be precomputed.
   
   bw - bandwidth
   m - order
   plmtable - precomputed associated Legendre functions
   coeffs - a pointer to double array of size (bw-m).  First coefficient is
            coefficient for Pmm
   result - a pointer to double array of size (2*bw) and containing the
            synthesized function

*/

void Naive_SynthesizeX(double *coeffs,
		       int bw,
		       int m,
		       double *result,
		       double *plmtable)
{
    int i, j;
    double tmpcoef;

    /* make sure result is zeroed out
    for (i=0; i<(2*bw); i++)
      result[i] = 0.0;
      */


    /* add in Pmm contribution */

    tmpcoef = coeffs[0];
    if (tmpcoef != 0.0)
      {
	if (m == 0)
	  for (j=0; j<(2*bw); j++)
	    result[j] = tmpcoef;
	else
	  for (j=0; j<(2*bw); j++)
	    result[j] = tmpcoef * plmtable[j];
      }

    plmtable += ( 2 * bw );

    /* now generate remaining pmls while synthesizing function */
    if (m == 0)
      {
	for (i=0; i<bw-m-1; i++) {
	  /* add in contribution  */
	  tmpcoef = coeffs[i+1] * 2.0;
	  if (tmpcoef != 0.0)
	    {
	      for (j=0; j<(2*bw); j++)
		result[j] += (tmpcoef * plmtable[j]);
	      plmtable += (2 * bw);
	    }
	}
      }
    else
      {
	for (i=0; i<bw-m-1; i++) {
	  /* add in contribution  */
	  tmpcoef = coeffs[i+1];
	  if (tmpcoef != 0.0)
	    {
	      for (j=0; j<(2*bw); j++)
		result[j] += (tmpcoef * plmtable[j]);
	      plmtable += (2 * bw);
	    }
	}
      }



}