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nbody_funcs.c
1454 lines (1143 loc) · 39.4 KB
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nbody_funcs.c
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#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<string.h>
#include<fftw3.h>
#include"nbody.h"
#include<omp.h>
/*---------------------GLOBAL VARIABLES declaration---------------------*/
// Cosmological parameters read from input file "input.zel"
extern float vhh, // Hubble parameter
vomegam, // Omega_matter; total matter density (baryons+CDM) parameter
vomegalam, // Cosmological Constant
vomegab, //Omega_baryon
tcmb, // CMB temperature
sigma_8_present ,// Last updated value of sigma_8 (Presently WMAP)
vnn; // Spectral index of primordial Power spectrum
extern long N1,N2,N3;// box dimension (grid)
extern int NF, // Fill every NF grid point
Nbin; // Number of bins to calculate final P(k) (output)
extern long MM; // Number of particles
extern float LL; // grid spacing in Mpc
// global variables (calculated )
extern int zel_flag, // memory allocation for zel is 3 times that for nbody
fourier_flag; //for fourier transfrom
extern float DM_m, // Darm matter mass of simulation particle (calculated)
norm, // normalize Pk
pi;
extern io_header header1; // structure for header
extern float ***ro; // for density or potential
extern fftwf_plan p_ro; // for FFT
extern fftwf_plan q_ro; // for FFT
// arrays for storing data
static float ***va; // for grad phi
static float norml, CC; // normalization constants
static float rho_b_inv, // (Mean number of particles/grid cell)^{-1}
Cx,Cy,Cz, // conversion from i,j,k to kx,ky,kz
Lcube,vol, // L^3, Volume=L^3*N1*N2*N3
tpibyL;// 2 pi /LL
static fftwf_plan q_va; // for FFT
static omp_lock_t *ro_lck;
/*********************************************************************************************************/
void Setting_Up_Memory_For_Ro(float av)
{
// for multiple threads
fftwf_init_threads();
fftwf_plan_with_nthreads(omp_get_max_threads());
// fftwf_plan_with_nthreads(1);
omp_set_num_threads(omp_get_max_threads());
// omp_set_num_threads(1);
printf("No of threads = %d\n",omp_get_max_threads());
// done multi thread
ro = allocate_fftwf_3d(N1,N2,N3+2);
va = allocate_fftwf_3d(N1,N2,N3+2); /* The last dimension gets padded because of using REAL FFT */
ro_lck=(omp_lock_t*)&(va[0][0][0]);
/****************************************************/
/* Creating the plans for forward and reverse FFT's */
p_ro = fftwf_plan_dft_r2c_3d(N1, N2, N3, &(ro[0][0][0]), (fftwf_complex*)&(ro[0][0][0]), FFTW_ESTIMATE);
q_ro = fftwf_plan_dft_c2r_3d(N1, N2, N3, (fftwf_complex*)&(ro[0][0][0]), &(ro[0][0][0]), FFTW_ESTIMATE);
q_va = fftwf_plan_dft_c2r_3d(N1, N2, N3, (fftwf_complex*)&(va[0][0][0]), &(va[0][0][0]), FFTW_ESTIMATE);
/****************************************************/
/* Fwd FFT followed immediately by Reverse FFT gives results reduced by a product N1*N2*N3 */
/* The FFT is unnormalized.. So we introduce a normalization factor */
norml=1./((1.0*N1)*(1.0*N2)*(1.0*N3));
Cx=2.*pi/(N1*LL); Cy=2.*pi/(N2*LL); Cz=2.*pi/(N3*LL);
Lcube=powf(LL,3.);
vol=Lcube/norml;
CC=pi*pi*vol*powf(Df(av),2.); // (2*pi^2 Volume DD^2)/2 DD-> initial growing mode
rho_b_inv=1.0/(norml*MM); // inverse of density in units of particles per unit cell
tpibyL=2.0*pi/LL;// 2 pi /LL
printf("norml=%e\tCC=%e\trho_b_inv=%e\n",norml,CC,rho_b_inv);
}
/*******************************************************************************************/
void delta_fill(long* seed)
{
long i,j,k,m,jj1,jj2,kk;
long index1,index2;
float amp,phasev,DD;
fftwf_complex *A;
float ran1(long*);
float gasdev(long*);
float p(long,long,long); // returns amplitude of delta(k)
A=(fftwf_complex*)&(ro[0][0][0]);
/********************FILLING POINTS***********************/
for(i=0;i<2;++i)
for(j=0;j<2;++j)
for(k=0;k<2;++k)
{
if (i==0 && j==0 && k==0)
{
index1=0;
A[index1][0]=0.0;
A[index1][1]=0.0;
}
else
{
index1 = i*(N1/2)*N2*(N3/2+1) + j*(N2/2)*(N3/2+1) + k*(N3/2);
amp=p(i*N1/2,j*N2/2,k*N3/2);
A[index1][0]=amp*gasdev(seed);
A[index1][1]=0.0;
}
}
/********************FILLING LINES***********************/
for(i=0;i<2;++i)
for(j=0;j<2;++j)
{
for(k=1;k<N1/2;k++)
{
amp=p(k,i*N2/2,j*N3/2);
index1 =k*N2*(N3/2+1) +i*(N2/2)*(N3/2+1) + j*(N3/2);
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
index2 =(N1-k)*N2*(N3/2+1) +i*(N2/2)*(N3/2+1) + j*(N3/2);
A[index2][1]=A[index1][0];
A[index2][1]=-A[index1][1];
}
for(k=1;k<N2/2;k++)
{
amp=p(i*N1/2,k,j*N3/2);
index1 =i*(N1/2)*N2*(N3/2+1)+ k*(N3/2+1) + j*(N3/2);
index2 =i*(N1/2)*N2*(N3/2+1)+(N2-k)*(N3/2+1) + j*(N3/2);
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
A[index2][0]=A[index1][0];
A[index2][1]=-A[index1][1];
}
for(k=1;k<N3/2;k++)
{
amp=p(i*N1/2,j*N2/2,k);
index1 =i*(N1/2)*N2*(N3/2+1)+ j*(N2/2)*(N3/2+1) + k;
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
}
}
/**********************FILLING PLANES***********************/
for(i=0;i<2;i++)
for(m=0;m<2;m++)
{
for(j=1;j<N2/2;j++)
for(k=1;k<N3/2;k++)
{
amp=p(i*N1/2,j,k);
jj1=(1-m)*j + m * (N2-j);
index1 =i*(N1/2)*N2*(N3/2+1)+ jj1*(N3/2+1) + k;
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
}
for(j=1;j<N1/2;j++)
for(k=1;k<N3/2;k++)
{
amp=p(j,i*N2/2,k);
jj1=(1-m)*j + m * (N1-j);
index1 =jj1*N2*(N3/2+1)+ i*(N2/2)*(N3/2+1) + k;
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
}
for(j=1;j<N1/2;j++)
for(k=1;k<N2/2;k++)
{
amp=p(j,k,i*N3/2);
jj1=(1-m)*j + m * (N1-j);
kk=k;
index1 =jj1*N2*(N3/2+1)+ kk*(N3/2+1)+i*N3/2;
jj2=m*j + (1-m) * (N1-j);
kk=N2-k;
index2 =jj2*N2*(N3/2+1)+ kk*(N3/2+1)+i*N3/2;
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
A[index2][0]=A[index1][0];
A[index2][1]=-A[index1][1];
}
}
/***************************FILLING CUBES***********************/
for(i=1;i<N1/2;i++)
for(j=1;j<N2/2;j++)
for(k=1;k<N3/2;k++)
{
amp=p(i,j,k);
index1 =i*N2*(N3/2+1) + j*(N3/2+1) + k;
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
index1 =(N1-i)*N2*(N3/2+1) + j*(N3/2+1) + k;
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
index1 =i*N2*(N3/2+1) + (N2-j)*(N3/2+1) + k;
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
index1 = (N1-i)*N2*(N3/2+1) + (N2-j)*(N3/2+1) + k;
A[index1][0]=amp*gasdev(seed);
A[index1][1]=amp*gasdev(seed);
}
}
/**************************************************************************************************/
float p(long i,long j,long k)
// returns amplitude of delta(k)
{
float kk,val,Pk(float),kx,ky,kz;
kx=Cx*i;
ky=Cy*j;
kz=Cz*k;
kk = (float)sqrt((double)(kx*kx+ ky*ky + kz*kz));
val = (float)sqrt(CC*Pk(kk));
return(val);
}
/*******************************************************************************************************/
/*******************************************************************************************************/
/******************** TO FIND POWER SPECTRUM **************************/
void calpow(int f_flag, int Nbin, double* power, double* powerk, double* kmode, long *no)
{
long i, j, k, a, b, c;
int d;
fftwf_complex *comp_ro;
float fac1,fac2,fac3, fac, m, scale;
long index,index1,index2,c1=0;
// f-flag==0 -> ro contains delta(k)
// f-flag==1 -> ro contains delta(x)
/*************** TAKING FOURIER TRANSFORM OF RO. **************/
// do forward transform to get delta(k)
if(f_flag==1)
{
for(i=0;i<N1;i++)
for(j=0;j<N2;j++)
for(k=0;k<N3;k++)
ro[i][j][k]=ro[i][j][k]*Lcube;
fftwf_execute(p_ro); // ro mow contains delta(k)
}
comp_ro = (fftwf_complex *)&(ro[0][0][0]);
/*********** TO FIND POWER SPECTRUM OF RO. **************/
fac1=1./(1.*N1*N1);
fac2=1./(1.*N2*N2);
fac3=1./(1.*N3*N3);
for(i=0;i<Nbin;++i)
{
power[i]=0.0;
powerk[i]=0.0;
kmode[i]=0.0;
no[i]=0;
}
// dor logarithmic bins
scale=log10(0.5*N1)/Nbin;
// ----------------------
/**************** BINNING POWER SPECTRA **********************/
/*-------------------------- half lines ------------------------- */
for(i=1;i<=N1/2;i++)
for(j=0;j<=N2/2;j=j+N2/2)
for(k=0;k<=N3/2;k=k+N3/2)
{
a=i;
b=j;
c=k;
index = i*N2*(N3/2+1) + j*(N3/2+1) + k;
m = sqrt(fac1*a*a + fac2*b*b + fac3*c*c);
d=(int)floorf(log10(m*N1)/scale);//logarithmic bins
if(d>=0 && d<Nbin)
{
power[d]+= ((comp_ro[index][0]* comp_ro[index][0]) + (comp_ro[index][1]* comp_ro[index][1]))*1.;
powerk[d] += Pk((float)(tpibyL*m))*1.0;
kmode[d] += m*1.;
no[d]=no[d]+1;
}
}
/*----------------------- half planes -----------------------*/
for(i=0;i<N1;i++)
{
a=(i>N1/2)? N1-i: i;
index1 = i*N2*(N3/2+1) ;
for(j=1;j<N2/2;j++)
{
b=j;
index2 = index1 + j*(N3/2+1) ;
for(k=0;k<=N3/2;k=k+N3/2)
{
c=k;
index = index2 + k;
m = sqrt(fac1*a*a + fac2*b*b + fac3*c*c);
d=(int)floorf(log10(m*N1)/scale);//logarithmic bins
if(d>=0 && d<Nbin)
{
power[d]+= ((comp_ro[index][0]* comp_ro[index][0]) + (comp_ro[index][1]* comp_ro[index][1]))*1.;
powerk[d] += Pk((float)(tpibyL*m))*1.0;
kmode[d] += m*1.;
no[d]=no[d]+1;
}
}
}
}
/**************** half cube **********************/
for(i=0;i<N1;i++)
{
a=(i>N1/2)? N1-i: i;
index1 = i*N2*(N3/2+1) ;
for(j=0;j<N2;j++)
{
b=(j>N2/2)? N2-j: j;
index2 = index1 + j*(N3/2+1) ;
for(k=1;k<N3/2;k++)
{
c=k;
index = index2 + k;
m = sqrt(fac1*a*a + fac2*b*b + fac3*c*c);
/* m*(2 * pi/LL) is |k| */
/* m=1/2 corresponds to kmode[Nbin-1] i.e. Nyquits */
d=(int)floorf(log10(m*N1)/scale);//logarithmic bins
if (d>=0 && d<Nbin)
{
power[d] += ((comp_ro[index][0]* comp_ro[index][0]) + (comp_ro[index][1]* comp_ro[index][1]))*1.;
powerk[d] += Pk((float)(tpibyL*m))*1.0;
kmode[d] += m*1.;
no[d]=no[d]+1;
}
} /* end k for loop */
}
}
for(i=0;i<Nbin;i++)
{
if (no[i]>0)
{
power[i] = power[i]/(1.*no[i]*vol);
powerk[i] = powerk[i]/(1.*no[i]);
kmode[i]=tpibyL*kmode[i]/(1.*no[i]);
}
}
// do back transform to get delta(x)
if(f_flag==1)
{
for(i=0;i<N1;i++)
{
index1 = i*N2*(N3/2+1) ;
for(j=0;j<N2;j++)
{
index2=index1 + j*(N3/2+1) ;
for(k=0;k<N3/2;k++)
{
index=index2 + k;
comp_ro[index][0]=comp_ro[index][0]/vol;
comp_ro[index][1]=comp_ro[index][1]/vol;
}
}
}
/* now convert the array back to real space */
fftwf_execute(q_ro);
}
}
/**********************************************************************/
/******************** TO FIND POWER SPECTRUM **************************/
void calpow_k(int f_flag, float kmin, float kmax, int Nbin,double* power, double* powerk, double* kmode, long *no)
{
long i, j, k, a, b, c;
int d;
fftwf_complex *comp_ro;
float fac1,fac2,fac3, fac, m, scale;
long index,index1,index2;
// f-flag==0 -> ro contains delta(k)
// f-flag==1 -> ro contains delta(x)
/*************** TAKING FOURIER TRANSFORM OF RO. **************/
// do forward transform to get delta(k)
if(f_flag==1)
{
for(i=0;i<N1;i++)
for(j=0;j<N2;j++)
for(k=0;k<N3;k++)
ro[i][j][k]=ro[i][j][k]*Lcube;
fftwf_execute(p_ro); // ro mow contains delta(k)
}
comp_ro = (fftwf_complex *)&(ro[0][0][0]);
/*********** TO FIND POWER SPECTRUM OF RO. **************/
fac1=1./(1.*N1*N1);
fac2=1./(1.*N2*N2);
fac3=1./(1.*N3*N3);
for(i=0;i<Nbin;++i)
{
power[i]=0.0;
powerk[i]=0.0;
kmode[i]=0.0;
no[i]=0;
}
// dor logarithmic bins
scale=(log10(kmax)-log10(kmin))/Nbin;
// ----------------------
/**************** BINNING POWER SPECTRA **********************/
/*-------------------------- half lines ------------------------- */
for(i=1;i<=N1/2;i++)
for(j=0;j<=N2/2;j=j+N2/2)
for(k=0;k<=N3/2;k=k+N3/2)
{
a=i;
b=j;
c=k;
index = i*N2*(N3/2+1) + j*(N3/2+1) + k;
m = tpibyL*sqrt(fac1*a*a + fac2*b*b + fac3*c*c); /* m is |k| */
d=(int)floorf((log10(m)-log10(kmin))/scale); //logarithmic bins
if(d>=0 && d<Nbin)
{
power[d]+= ((comp_ro[index][0]* comp_ro[index][0]) + (comp_ro[index][1]* comp_ro[index][1]))*1.;
powerk[d] += Pk((float)(m))*1.0;
kmode[d] += m*1.;
no[d]=no[d]+1;
}
}
/*----------------------- half planes -----------------------*/
for(i=0;i<N1;i++)
{
a=(i>N1/2)? N1-i: i;
index1 = i*N2*(N3/2+1) ;
for(j=1;j<N2/2;j++)
{
b=j;
index2 = index1 + j*(N3/2+1) ;
for(k=0;k<=N3/2;k=k+N3/2)
{
c=k;
index = index2 + k;
m = tpibyL*sqrt(fac1*a*a + fac2*b*b + fac3*c*c); /* m is |k| */
d=(int)floorf((log10(m)-log10(kmin))/scale); //logarithmic bins
if(d>=0 && d<Nbin)
{
power[d]+= ((comp_ro[index][0]* comp_ro[index][0]) + (comp_ro[index][1]* comp_ro[index][1]))*1.;
powerk[d] += Pk((float)(m))*1.0;
kmode[d] += m*1.;
no[d]=no[d]+1;
}
}
}
}
/**************** half cube **********************/
for(i=0;i<N1;i++)
{
a=(i>N1/2)? N1-i: i;
index1 = i*N2*(N3/2+1) ;
for(j=0;j<N2;j++)
{
b=(j>N2/2)? N2-j: j;
index2 = index1 + j*(N3/2+1) ;
for(k=1;k<N3/2;k++)
{
c=k;
index = index2 + k;
m = tpibyL*sqrt(fac1*a*a + fac2*b*b + fac3*c*c); /* m is |k| */
d=(int)floorf((log10(m)-log10(kmin))/scale); //logarithmic bins
if (d>=0 && d<Nbin)
{
power[d] += ((comp_ro[index][0]* comp_ro[index][0]) + (comp_ro[index][1]* comp_ro[index][1]))*1.;
powerk[d] += Pk((float)(m))*1.0;
kmode[d] += m*1.;
no[d]=no[d]+1;
}
} /* end k for loop */
}
}
for(i=0;i<Nbin;i++)
{
if (no[i]>0)
{
power[i] = power[i]/(1.*no[i]*vol);
powerk[i] = powerk[i]/(1.*no[i]);
kmode[i] = kmode[i]/(1.*no[i]);
}
}
// do back transform to get delta(x)
if(f_flag==1)
{
for(i=0;i<N1;i++)
{
index1 = i*N2*(N3/2+1) ;
for(j=0;j<N2;j++)
{
index2=index1 + j*(N3/2+1) ;
for(k=0;k<N3/2;k++)
{
index=index2 + k;
comp_ro[index][0]=comp_ro[index][0]/vol;
comp_ro[index][1]=comp_ro[index][1]/vol;
}
}
}
/* now convert the array back to real space */
fftwf_execute(q_ro);
}
}
/*******************************************************************************************************/
/*******************************************************************************************************/
void grad_phi(int ix)
{
// at start of this function: ro contains delta(k)
// at end of function va contains the ix component of Grad[Laplacian^-1[delta(x)]]
// this is used in ZA
long ii,jj,kk;
long index;
float AA,a0,a1,a2;
fftwf_complex *vc,*roc;
vc=(fftwf_complex*)&(va[0][0][0]);
roc=(fftwf_complex*)&(ro[0][0][0]);
#pragma omp parallel for private(jj,kk,a0,a1,a2,AA,index)
for(ii=0;ii<N1;ii++)
{
a0 = (ii>N1/2)? Cx*(ii-N1) : Cx*ii; // kx
for(jj=0;jj<N2;jj++)
{
a1 = (jj>N2/2)? Cy*(jj-N2) : Cy*jj; // ky
kk=0;
a2=0.;
index = (ii*N2+jj)*(N3/2+1) + kk;
AA = pow(a0,2.)+pow(a1,2.)+pow(a2,2.); // AA=K^2
AA = (fabs(AA)>1.e-10)? (((ix-1)*(ix-2)/2)*a0 - ix*(ix-2)*a1 + (ix*(ix-1)/2)*a2)/AA : 0.0; // AA=k_ix/K^2 or 0
vc[index][0]=-1.0*AA*roc[index][1]/vol;
vc[index][1]=AA*roc[index][0]/vol;
for(kk=1;kk<N3/2+1;kk++)
{
a2=kk*Cz; // kz
index = (ii*N2+jj)*(N3/2+1) + kk;
AA= pow(a0,2.)+pow(a1,2.)+pow(a2,2.); // AA=K^2
AA=(((ix-1)*(ix-2)/2)*a0 - ix*(ix-2)*a1 + (ix*(ix-1)/2)*a2)/AA; // AA=k_ix/K^2
vc[index][0] = -1.0*AA*roc[index][1]/vol;
vc[index][1] = AA*roc[index][0]/vol;
}
}
}
fftwf_execute(q_va); /* Take fourier transform */
}
//############################################################################################
//############################################################################################
void Zel_move_gradphi(float av,float **rra,float **vva)
{
float DD, // growing mode
vfac; // converts to peculiar velocity
int ii;
long jj, kk, ll, N, pos;
long pin;
vfac = av*av*Hf(av)*ff(av)/LL;
for(ii=0;ii<3;++ii)
{
grad_phi(ii); // Calculate ix component of -Grad[Laplacian^{_1}[delta]] in real space
#pragma omp parallel for private(jj,kk,ll,pos,pin,N)
for(jj=0;jj<N1/NF;jj++)
for(kk=0;kk<N2/NF;kk++)
for(ll=0;ll<N3/NF;ll++)
{
pin = jj*(N2/NF)*(N3/NF) + kk*(N3/NF) + ll;
pos= (ii-1)*(ii-2)*jj/2 - ii*(ii-2)*kk + ii*(ii-1)*ll/2;
rra[pin][ii]=(float)(NF*pos)+ va[NF*jj][NF*kk][NF*ll]/LL;
vva[pin][ii]=vfac*va[NF*jj][NF*kk][NF*ll];
// periodic boundary condition
N = (ii-1)*(ii-2)*N1/2 - ii*(ii-2)*N2 + ii*(ii-1)*N3/2;
/* to ensure the values are not negative */
rra[pin][ii]=rra[pin][ii]+N;
rra[pin][ii]= rra[pin][ii]-1.0*N*(int)(floor(rra[pin][ii])/(1.*N));
}
/*------------------- done ---------------------*/
}
} /* end of Zel_move_gradphi */
//######################################################################################
void cic(float **rra)
// //For a given particle distribution
// This uses Cloud in Cell(CIC) to calculate (1 + delta) on the Grid
{
long i, j, k, ix, jy, kz;
int ii, jj, kk;
long pin,index;
float wx,wy,wz;
/* Clear out the array ro. ******/
#pragma omp parallel for private(i,j,k,index)
for(i=0;i<N1;i++)
for(j=0;j<N2;j++)
for(k=0;k<N3;k++)
{
index = (i*N2+j)*N3 + k;
ro[i][j][k] = 0.0;
omp_init_lock(&ro_lck[index]);
}
/********************************/
#pragma omp parallel for private(i, j, k, ii, jj, kk, wx, ix, wy, jy, wz, kz, index)
for(pin=0;pin<MM;pin++)
{ /* begin particle index loop */
/* (a/b/c)[0] or (a/b/c)[1] can never be greater than (N1/N2/N3) */
// left bottom corner of cell containing the particle
i = (long)floor(rra[pin][0]);
j = (long)floor(rra[pin][1]);
k = (long)floor(rra[pin][2]);
/* for each of the 8 corner points */
for(ii=0;ii<=1;ii++)
{
wx=fabs(1.-rra[pin][0]+i-ii)*rho_b_inv; // divide by mean density
ix=(i+ii)%N1;
for(jj=0;jj<=1;jj++)
{
wy=fabs(1.-rra[pin][1]+j-jj);
jy=(j+jj)%N2;
for(kk=0;kk<=1;kk++)
{
wz=fabs(1.-rra[pin][2]+k-kk);
kz=(k+kk)%N3;
index=(ix*N2+jy)*N3 + kz;
omp_set_lock(&ro_lck[index]);
ro[ix][jy][kz]+=wx*wy*wz;
omp_unset_lock(&ro_lck[index]);
}
}
} /* end of 8 grid corners loop> */
} /* end of each particle loop */
} /* end of function cic */
//############################################################################################
//############################################################################################
void cic_sampled(float **rra, int *s_indx)
// //For a given particle distribution
// This uses Cloud in Cell(CIC) to calculate (1 + delta) on the Grid
{
long i, j, k, ix, jy, kz;
int ii, jj, kk;
long pin,index;
float wx,wy,wz;
/* Clear out the array ro. ******/
#pragma omp parallel for private(i,j,k,index)
for(i=0;i<N1;i++)
for(j=0;j<N2;j++)
for(k=0;k<N3;k++)
{
index = (i*N2+j)*N3 + k;
ro[i][j][k] = 0.0;
omp_init_lock(&ro_lck[index]);
}
/********************************/
#pragma omp parallel for private(i, j, k, ii, jj, kk, wx, ix, wy, jy, wz, kz, index)
for(pin=0;pin<MM;pin++)
if(s_indx[pin]==-1)
{ /* begin particle index loop */
/* (a/b/c)[0] or (a/b/c)[1] can never be greater than (N1/N2/N3) */
// left bottom corner of cell containing the particle
i = (long)floor(rra[pin][0]);
j = (long)floor(rra[pin][1]);
k = (long)floor(rra[pin][2]);
/* for each of the 8 corner points */
for(ii=0;ii<=1;ii++)
{
wx=fabs(1.-rra[pin][0]+i-ii)*rho_b_inv; // divide by mean density
ix=(i+ii)%N1;
for(jj=0;jj<=1;jj++)
{
wy=fabs(1.-rra[pin][1]+j-jj);
jy=(j+jj)%N2;
for(kk=0;kk<=1;kk++)
{
wz=fabs(1.-rra[pin][2]+k-kk);
kz=(k+kk)%N3;
index=(ix*N2+jy)*N3 + kz;
omp_set_lock(&ro_lck[index]);
ro[ix][jy][kz]+=wx*wy*wz;
omp_unset_lock(&ro_lck[index]);
}
}
} /* end of 8 grid corners loop> */
} /* end of each particle loop */
} /* end of function cic_sampled */
//##########################################################################################
void Get_phi(int f_flag) // calculates Laplacian^{-1}[ ro]]
{
long ii,jj,kk;
long index;
float AA,a0,a1,a2;
fftwf_complex *roc;
/*************** TAKING FOURIER TRANSFORM OF RO. **************/
// do forward transform to get ro(k)
if(f_flag==1)
{
for(ii=0;ii<N1;ii++)
for(jj=0;jj<N2;jj++)
for(kk=0;kk<N3;kk++)
ro[ii][jj][kk]*=Lcube;
fftwf_execute(p_ro); // ro mow contains delta(k)
}
//------------------------------------------
roc=(fftwf_complex*)&(ro[0][0][0]);
#pragma omp parallel for private(jj,kk,a0,a1,a2,AA,index)
for(ii=0;ii<N1;ii++)
{
a0=ii*pi/N1; // kx *LL/2
a0=pow(2.*sin(a0)/LL,2.);
for(jj=0;jj<N2;jj++)
{
a1=jj*pi/N2; // ky *LL/2
a1=pow(2.*sin(a1)/LL,2.);
kk=0;
index = (ii*N2+jj)*(N3/2+1) + kk;
AA=a0+a1;
AA=(fabs(AA)>1.e-10)? 1/AA:0.; // AA=k_ix/K^2 or 0
roc[index][0] = -1.*AA*roc[index][0]/vol;
roc[index][1] = -1.*AA*roc[index][1]/vol;
for(kk=1;kk<N3/2+1;kk++)
{
a2=kk*pi/N3; // kz *LL/2
a2=pow(2.*sin(a2)/LL,2.);
index = (ii*N2+jj)*(N3/2+1) + kk;
AA=1./(a0+a1+a2);
roc[index][0] = -1.*AA*roc[index][0]/vol;
roc[index][1] = -1.*AA*roc[index][1]/vol;
}
}
}
fftwf_execute(q_ro); /* Take fourier transform */
}
//#############################################################################################
void Update_v(float av,float delta_aa,float **rra,float **vva) // udates v if (delta a >0) else intializes v
{
long pin;
int ii,jj,kk;
long xp,yp,zp,xn,yn,zn; /* (x/y/z)(p/n) = (x/y/z)(previous/next) */
long a,b,c,ix,jy,kz;
float wx,wy,wz,g0,g1,g2;
float xx,yy,zz;
float coeff,Hf(float aa),vflag;
cic(rra); // calculate delta(x) from particle distribution
Get_phi(1);// Calculate [Laplacian^{_1}[delta]] in real space
if(delta_aa>0.)
{
coeff=delta_aa*1.5* vomegam/(LL*av*av*Hf(av)); // delta_aa scaled
vflag=1.0;
}
else
{
coeff = av*av*Hf(av)*ff(av)/LL;
vflag=0.0;
}
coeff/=(2.*LL); // divide by 2 LL for Grad on grid
#pragma omp parallel for private(a,b,c,xx,yy,zz,g0,g1,g2,ii,jj,kk,ix,wx,xp,xn,jy,wy,yn,yp,kz,wz,zp,zn)
for(pin=0;pin<MM;pin++)
{
/* left most corner of the cube enclosing the particle */
a = (long)floor(rra[pin][0]);
b = (long)floor(rra[pin][1]);
c = (long)floor(rra[pin][2]);
/* particle co-ordinates itself */
xx = rra[pin][0];
yy = rra[pin][1];
zz = rra[pin][2];
g0=0;
g1=0;
g2=0;
/* begin 8 corners loop */
for(ii=0;ii<=1;ii++)
{
ix = (a+ii)%N1;
wx=fabs(1.- xx +a-ii);
xp = ((ix-1)==-1) ? N1-1: ix-1;
xn = ((ix+1)==N1) ? 0 : ix+1;
for(jj=0;jj<=1;jj++)
{
jy = (b+jj)%N2;
wy=fabs(1.- yy +b-jj);
yp = ((jy-1)==-1) ? N2-1: jy-1;
yn = ((jy+1)==N2) ? 0 : jy+1;
for(kk=0;kk<=1;kk++)
{
kz = (c+kk)%N3;
wz=fabs(1.- zz +c-kk);
zp = ((kz-1)==-1) ? N3-1: kz-1;
zn = ((kz+1)==N3) ? 0 : kz+1;
/* ix,jy,kz are the current co-ordinates of the cube vertex point */
/* calculating the difference from the respective corner */