#include <stdio.h>
#include <stddef.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <math.h>
#include "geostat.h"
#include "pressure.h"

/* Build_pressure                                       */
/* build pressure in spectral domain                         */

void build_pressure(int n[3],struct grid_mod grid,struct pressure_mod gradient,double *realization,double *ireal,double *pressure,double *ipressure)
{
  int i,j,k,maille1;
  double ki,kj,kk;
  double coeff,temp,temp2;

  printf("build pressure pdslis\n");

      	/* pressure calculation in the spectral domain*/
	for ( k = 1; k <= n[2]; k++) {
	  for (j = 1; j <= n[1]; j++) {
	    for (i = 1; i <= n[0]; i++) {
	      maille1 = i+(j-1+(k-1)*n[1])*n[0];
	      if (n[0]==1)
		{
		  ki=0.;
		}
	       else
		 {
		   ki =(double)(i-1)/(double)(grid.NX*grid.DX);
		 }
	      if (n[1]==1)
		{
		  kj=0.;
		}
	      else
		{
		  kj =(double)j/(double)(grid.NY*grid.DY);
		}
	      if (n[2]==1)
		{
		  kk=0.;
		}
	      else
		{
		  kk =(double)k/(double)(grid.NZ*grid.DZ);
		}

	      coeff = (gradient.x*ki+gradient.y*kj+gradient.z*kk)/(ki*ki+kj*kj+kk*kk);
	      temp = realization[maille1];
	      temp2= ireal[maille1];
	      if (maille1==1)
		{
		  pressure[maille1] =0.;
		  ipressure[maille1]=0.;
		}
	      else
		{
		  pressure[maille1] =-1./(2*3.14)*coeff*temp2;
		  ipressure[maille1]= 1./(2*3.14)*coeff*temp;
		}
	    }
	  }
	}
  return;
}