Пример #1
0
// ---------------------------------------------------------------------------------------------------------------------
//! Project global current charge
// ---------------------------------------------------------------------------------------------------------------------
void Projector1D1Order::operator() (Field* rho, Particles &particles, int ipart)
{
    Field1D* rho1D  = static_cast<Field1D*>(rho);


    //Declaration of local variables
    int i;
    double xjn,xjmxi;
    double rho_j = particles.charge(ipart)*particles.weight(ipart);  // charge density of the macro-particle


    //Locate particle on the grid
    xjn    = particles.position(0, ipart) * dx_inv_;  // normalized distance to the first node
    i      = floor(xjn);                   // index of the central node
    xjmxi  = xjn - (double)i;              // normalized distance to the nearest grid point

    //cout << "Pos = " << particles.position(0, ipart) << " - i global = " << i << " - i local = " << i-index_domain_begin <<endl;

    i -= index_domain_begin;

    // 1nd order projection for the total density
    //#pragma omp atomic
    (*rho1D)( i  )  += (1.0 - xjmxi)    * rho_j ;
    //#pragma omp atomic
    (*rho1D)( i+1)  += xjmxi             * rho_j;

} // END Project global current charge
Пример #2
0
// ---------------------------------------------------------------------------------------------------------------------
//! Project current densities : main projector
// ---------------------------------------------------------------------------------------------------------------------
void Projector2D4Order::currents( double *Jx, double *Jy, double *Jz, Particles &particles, unsigned int ipart, double invgf, int *iold, double *deltaold )
{
    int nparts = particles.size();
    
    // -------------------------------------
    // Variable declaration & initialization
    // -------------------------------------
    
    int iloc;
    // (x,y,z) components of the current density for the macro-particle
    double charge_weight = inv_cell_volume * ( double )( particles.charge( ipart ) )*particles.weight( ipart );
    double crx_p = charge_weight*dx_ov_dt;
    double cry_p = charge_weight*dy_ov_dt;
    double crz_p = charge_weight*one_third*particles.momentum( 2, ipart )*invgf;
    
    // variable declaration
    double xpn, ypn;
    double delta, delta2, delta3, delta4;
    // arrays used for the Esirkepov projection method
    double  Sx0[7], Sx1[7], Sy0[7], Sy1[7], DSx[7], DSy[7], tmpJx[7];
    
    for( unsigned int i=0; i<7; i++ ) {
        Sx1[i] = 0.;
        Sy1[i] = 0.;
        tmpJx[i] = 0.;
    }
    Sx0[0] = 0.;
    Sx0[6] = 0.;
    Sy0[0] = 0.;
    Sy0[6] = 0.;
    
    // --------------------------------------------------------
    // Locate particles & Calculate Esirkepov coef. S, DS and W
    // --------------------------------------------------------
    
    // locate the particle on the primal grid at former time-step & calculate coeff. S0
    delta = deltaold[0*nparts];
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    
    Sx0[1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sx0[2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx0[3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sx0[4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx0[5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    
    delta = deltaold[1*nparts];
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    
    Sy0[1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sy0[2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy0[3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sy0[4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy0[5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    
    
    // locate the particle on the primal grid at current time-step & calculate coeff. S1
    xpn = particles.position( 0, ipart ) * dx_inv_;
    int ip = round( xpn );
    int ipo = iold[0*nparts];
    int ip_m_ipo = ip-ipo-i_domain_begin;
    delta  = xpn - ( double )ip;
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    
    Sx1[ip_m_ipo+1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sx1[ip_m_ipo+2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx1[ip_m_ipo+3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sx1[ip_m_ipo+4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx1[ip_m_ipo+5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    
    ypn = particles.position( 1, ipart ) * dy_inv_;
    int jp = round( ypn );
    int jpo = iold[1*nparts];
    int jp_m_jpo = jp-jpo-j_domain_begin;
    delta  = ypn - ( double )jp;
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    
    Sy1[jp_m_jpo+1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sy1[jp_m_jpo+2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy1[jp_m_jpo+3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sy1[jp_m_jpo+4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy1[jp_m_jpo+5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    
    for( unsigned int i=0; i < 7; i++ ) {
        DSx[i] = Sx1[i] - Sx0[i];
        DSy[i] = Sy1[i] - Sy0[i];
    }
    
    // calculate Esirkepov coeff. Wx, Wy, Wz when used
    double tmp, tmp2, tmp3, tmpY;
    //Do not compute useless weights.
    // ------------------------------------------------
    // Local current created by the particle
    // calculate using the charge conservation equation
    // ------------------------------------------------
    
    // ---------------------------
    // Calculate the total current
    // ---------------------------
    ipo -= 3; //This minus 3 come from the order 4 scheme, based on a 7 points stencil from -3 to +3.
    jpo -= 3;
    // i =0
    {
        iloc = ipo*nprimy+jpo;
        tmp2 = 0.5*Sx1[0];
        tmp3 =     Sx1[0];
        Jz[iloc]  += crz_p * ( Sy1[0]*tmp3 );
        tmp = 0;
        tmpY = Sx0[0] + 0.5*DSx[0];
        for( unsigned int j=1 ; j<7 ; j++ ) {
            tmp -= cry_p * DSy[j-1] * tmpY;
            Jy[iloc+j+ipo]  += tmp; //Because size of Jy in Y is nprimy+1.
            Jz[iloc+j]  += crz_p * ( Sy0[j]*tmp2 + Sy1[j]*tmp3 );
        }
    }//i
    
    for( unsigned int i=1 ; i<7 ; i++ ) {
        iloc = ( i+ipo )*nprimy+jpo;
        tmpJx[0] -= crx_p *  DSx[i-1] * ( 0.5*DSy[0] );
        Jx[iloc]  += tmpJx[0];
        tmp2 = 0.5*Sx1[i] + Sx0[i];
        tmp3 = 0.5*Sx0[i] + Sx1[i];
        Jz[iloc]  += crz_p * ( Sy1[0]*tmp3 );
        tmp = 0;
        tmpY = Sx0[i] + 0.5*DSx[i];
        for( unsigned int j=1 ; j<7 ; j++ ) {
            tmpJx[j] -= crx_p * DSx[i-1] * ( Sy0[j] + 0.5*DSy[j] );
            Jx[iloc+j]  += tmpJx[j];
            tmp -= cry_p * DSy[j-1] * tmpY;
            Jy[iloc+j+i+ipo]  += tmp; //Because size of Jy in Y is nprimy+1.
            Jz[iloc+j]  += crz_p * ( Sy0[j]*tmp2 + Sy1[j]*tmp3 );
        }
    }//i
    
}
Пример #3
0
// ---------------------------------------------------------------------------------------------------------------------
//! Project charge : frozen & diagFields timstep
// ---------------------------------------------------------------------------------------------------------------------
void Projector2D4Order::basic( double *rhoj, Particles &particles, unsigned int ipart, unsigned int type )
{
    //Warning : this function is used for frozen species or initialization only and doesn't use the standard scheme.
    //rho type = 0
    //Jx type = 1
    //Jy type = 2
    //Jz type = 3
    
    int iloc;
    int ny( nprimy );
    // (x,y,z) components of the current density for the macro-particle
    double charge_weight = inv_cell_volume * ( double )( particles.charge( ipart ) )*particles.weight( ipart );
    
    if( type > 0 ) {
        charge_weight *= 1./sqrt( 1.0 + particles.momentum( 0, ipart )*particles.momentum( 0, ipart )
                                  + particles.momentum( 1, ipart )*particles.momentum( 1, ipart )
                                  + particles.momentum( 2, ipart )*particles.momentum( 2, ipart ) );
                                  
        if( type == 1 ) {
            charge_weight *= particles.momentum( 0, ipart );
        } else if( type == 2 ) {
            charge_weight *= particles.momentum( 1, ipart );
            ny ++;
        } else {
            charge_weight *= particles.momentum( 2, ipart );
        }
    }
    
    // variable declaration
    double xpn, ypn;
    double delta, delta2, delta3, delta4;
    // arrays used for the Esirkepov projection method
    double  Sx1[7], Sy1[7];
    
    for( unsigned int i=0; i<7; i++ ) {
        Sx1[i] = 0.;
        Sy1[i] = 0.;
    }
    
    // --------------------------------------------------------
    // Locate particles & Calculate Esirkepov coef. S, DS and W
    // --------------------------------------------------------
    // locate the particle on the primal grid at current time-step & calculate coeff. S1
    xpn = particles.position( 0, ipart ) * dx_inv_;
    int ip        = round( xpn + 0.5 * ( type==1 ) );                       // index of the central node
    delta  = xpn - ( double )ip;
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    
    Sx1[1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sx1[2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx1[3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sx1[4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx1[5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    
    ypn = particles.position( 1, ipart ) * dy_inv_;
    int jp = round( ypn + 0.5*( type==2 ) );
    delta  = ypn - ( double )jp;
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    
    Sy1[1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sy1[2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy1[3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sy1[4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy1[5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    
    // ---------------------------
    // Calculate the total current
    // ---------------------------
    ip -= i_domain_begin + 3;
    jp -= j_domain_begin + 3;
    
    for( unsigned int i=0 ; i<7 ; i++ ) {
        iloc = ( i+ip )*ny+jp;
        for( unsigned int j=0 ; j<7 ; j++ ) {
            rhoj[iloc+j] += charge_weight * Sx1[i]*Sy1[j];
        }
    }//i
}
Пример #4
0
// ---------------------------------------------------------------------------------------------------------------------
//! Project current densities : main projector
// ---------------------------------------------------------------------------------------------------------------------
void Projector1D4Order::currents( double *Jx, double *Jy, double *Jz, Particles &particles, unsigned int ipart, double invgf, int *iold, double *delta )
{
    // Declare local variables
    int ipo, ip;
    int ip_m_ipo;
    double charge_weight = inv_cell_volume * ( double )( particles.charge( ipart ) )*particles.weight( ipart );
    double xjn, xj_m_xipo, xj_m_xipo2, xj_m_xipo3, xj_m_xipo4, xj_m_xip, xj_m_xip2, xj_m_xip3, xj_m_xip4;
    double crx_p = charge_weight*dx_ov_dt;                // current density for particle moving in the x-direction
    double cry_p = charge_weight*particles.momentum( 1, ipart )*invgf;  // current density in the y-direction of the macroparticle
    double crz_p = charge_weight*particles.momentum( 2, ipart )*invgf;  // current density allow the y-direction of the macroparticle
    double S0[7], S1[7], Wl[7], Wt[7], Jx_p[7];            // arrays used for the Esirkepov projection method
    // Initialize variables
    for( unsigned int i=0; i<7; i++ ) {
        S0[i]=0.;
        S1[i]=0.;
        Wl[i]=0.;
        Wt[i]=0.;
        Jx_p[i]=0.;
    }//i
    
    
    // Locate particle old position on the primal grid
    xj_m_xipo  = *delta;                   // normalized distance to the nearest grid point
    xj_m_xipo2 = xj_m_xipo  * xj_m_xipo;                 // square of the normalized distance to the nearest grid point
    xj_m_xipo3 = xj_m_xipo2 * xj_m_xipo;              // cube of the normalized distance to the nearest grid point
    xj_m_xipo4 = xj_m_xipo3 * xj_m_xipo;              // 4th power of the normalized distance to the nearest grid point
    
    // Locate particle new position on the primal grid
    xjn       = particles.position( 0, ipart ) * dx_inv_;
    ip        = round( xjn );                         // index of the central node
    xj_m_xip  = xjn - ( double )ip;                   // normalized distance to the nearest grid point
    xj_m_xip2 = xj_m_xip  * xj_m_xip;                    // square of the normalized distance to the nearest grid point
    xj_m_xip3 = xj_m_xip2 * xj_m_xip;                 // cube of the normalized distance to the nearest grid point
    xj_m_xip4 = xj_m_xip3 * xj_m_xip;                 // 4th power of the normalized distance to the nearest grid point
    
    
    // coefficients 4th order interpolation on 5 nodes
    
    S0[1] = dble_1_ov_384   - dble_1_ov_48  * xj_m_xipo  + dble_1_ov_16 * xj_m_xipo2 - dble_1_ov_12 * xj_m_xipo3 + dble_1_ov_24 * xj_m_xipo4;
    S0[2] = dble_19_ov_96   - dble_11_ov_24 * xj_m_xipo  + dble_1_ov_4 * xj_m_xipo2  + dble_1_ov_6  * xj_m_xipo3 - dble_1_ov_6  * xj_m_xipo4;
    S0[3] = dble_115_ov_192 - dble_5_ov_8   * xj_m_xipo2 + dble_1_ov_4 * xj_m_xipo4;
    S0[4] = dble_19_ov_96   + dble_11_ov_24 * xj_m_xipo  + dble_1_ov_4 * xj_m_xipo2  - dble_1_ov_6  * xj_m_xipo3 - dble_1_ov_6  * xj_m_xipo4;
    S0[5] = dble_1_ov_384   + dble_1_ov_48  * xj_m_xipo  + dble_1_ov_16 * xj_m_xipo2 + dble_1_ov_12 * xj_m_xipo3 + dble_1_ov_24 * xj_m_xipo4;
    
    // coefficients 2nd order interpolation on 5 nodes
    ipo        = *iold;                          // index of the central node
    ip_m_ipo = ip-ipo-index_domain_begin;
    
    S1[ip_m_ipo+1] = dble_1_ov_384   - dble_1_ov_48  * xj_m_xip  + dble_1_ov_16 * xj_m_xip2 - dble_1_ov_12 * xj_m_xip3 + dble_1_ov_24 * xj_m_xip4;
    S1[ip_m_ipo+2] = dble_19_ov_96   - dble_11_ov_24 * xj_m_xip  + dble_1_ov_4 * xj_m_xip2  + dble_1_ov_6  * xj_m_xip3 - dble_1_ov_6  * xj_m_xip4;
    S1[ip_m_ipo+3] = dble_115_ov_192 - dble_5_ov_8   * xj_m_xip2 + dble_1_ov_4 * xj_m_xip4;
    S1[ip_m_ipo+4] = dble_19_ov_96   + dble_11_ov_24 * xj_m_xip  + dble_1_ov_4 * xj_m_xip2  - dble_1_ov_6  * xj_m_xip3 - dble_1_ov_6  * xj_m_xip4;
    S1[ip_m_ipo+5] = dble_1_ov_384   + dble_1_ov_48  * xj_m_xip  + dble_1_ov_16 * xj_m_xip2 + dble_1_ov_12 * xj_m_xip3 + dble_1_ov_24 * xj_m_xip4;
    
    // coefficients used in the Esirkepov method
    for( unsigned int i=0; i<7; i++ ) {
        Wl[i] = S0[i] - S1[i];           // for longitudinal current (x)
        Wt[i] = 0.5 * ( S0[i] + S1[i] ); // for transverse currents (y,z)
    }//i
    
    // local current created by the particle
    // calculate using the charge conservation equation
    for( unsigned int i=1; i<7; i++ ) {
        Jx_p[i] = Jx_p[i-1] + crx_p * Wl[i-1];
    }
    
    ipo -= 3 ;
    
    // 4th order projection for the total currents & charge density
    // At the 4th order, oversize = 3.
    for( unsigned int i=0; i<7; i++ ) {
        Jx[i  + ipo]  += Jx_p[i];
        Jy[i  + ipo]  += cry_p * Wt[i];
        Jz[i  + ipo]  += crz_p * Wt[i];
    }//i
    
}
Пример #5
0
// ---------------------------------------------------------------------------------------------------------------------
//! Project charge : frozen & diagFields timstep
// ---------------------------------------------------------------------------------------------------------------------
void Projector1D4Order::basic( double *rhoj, Particles &particles, unsigned int ipart, unsigned int type )
{

    //Warning : this function is used for frozen species or initialization only and doesn't use the standard scheme.
    //rho type = 0
    //Jx type = 1
    //Jy type = 2
    //Jz type = 3
    
    
    // Declare local variables
    //int ipo, ip, iloc;
    int ip;
    //int ip_m_ipo;
    double charge_weight = inv_cell_volume * ( double )( particles.charge( ipart ) )*particles.weight( ipart );
    double xjn, xj_m_xip, xj_m_xip2, xj_m_xip3, xj_m_xip4;
    double S1[7];            // arrays used for the Esirkepov projection method
    // Initialize variables
    for( unsigned int i=0; i<7; i++ ) {
        S1[i]=0.;
    }//i
    
    if( type > 0 ) {
        charge_weight *= 1./sqrt( 1.0 + particles.momentum( 0, ipart )*particles.momentum( 0, ipart )
                                  + particles.momentum( 1, ipart )*particles.momentum( 1, ipart )
                                  + particles.momentum( 2, ipart )*particles.momentum( 2, ipart ) );
                                  
        if( type == 1 ) {
            charge_weight *= particles.momentum( 0, ipart );
        } else if( type == 2 ) {
            charge_weight *= particles.momentum( 1, ipart );
        } else {
            charge_weight *= particles.momentum( 2, ipart );
        }
    }
    
    // Locate particle new position on the primal grid
    xjn       = particles.position( 0, ipart ) * dx_inv_;
    ip        = round( xjn + 0.5 * ( type==1 ) );                       // index of the central node
    xj_m_xip  = xjn - ( double )ip;                   // normalized distance to the nearest grid point
    xj_m_xip2 = xj_m_xip  * xj_m_xip;                    // square of the normalized distance to the nearest grid point
    xj_m_xip3 = xj_m_xip2 * xj_m_xip;                 // cube of the normalized distance to the nearest grid point
    xj_m_xip4 = xj_m_xip3 * xj_m_xip;                 // 4th power of the normalized distance to the nearest grid point
    
    // coefficients 2nd order interpolation on 5 nodes
    //ip_m_ipo = ip-ipo;
    
    S1[1] = dble_1_ov_384   - dble_1_ov_48  * xj_m_xip  + dble_1_ov_16 * xj_m_xip2 - dble_1_ov_12 * xj_m_xip3 + dble_1_ov_24 * xj_m_xip4;
    S1[2] = dble_19_ov_96   - dble_11_ov_24 * xj_m_xip  + dble_1_ov_4 * xj_m_xip2  + dble_1_ov_6  * xj_m_xip3 - dble_1_ov_6  * xj_m_xip4;
    S1[3] = dble_115_ov_192 - dble_5_ov_8   * xj_m_xip2 + dble_1_ov_4 * xj_m_xip4;
    S1[4] = dble_19_ov_96   + dble_11_ov_24 * xj_m_xip  + dble_1_ov_4 * xj_m_xip2  - dble_1_ov_6  * xj_m_xip3 - dble_1_ov_6  * xj_m_xip4;
    S1[5] = dble_1_ov_384   + dble_1_ov_48  * xj_m_xip  + dble_1_ov_16 * xj_m_xip2 + dble_1_ov_12 * xj_m_xip3 + dble_1_ov_24 * xj_m_xip4;
    
    ip -= index_domain_begin + 3 ;
    
    // 4th order projection for the charge density
    // At the 4th order, oversize = 3.
    for( unsigned int i=0; i<7; i++ ) {
        //iloc = i  + ipo - 3;
        rhoj[i  + ip ] += charge_weight * S1[i];
    }//i
    
}
Пример #6
0
// ---------------------------------------------------------------------------------------------------------------------
//! Project local currents (sort)
// ---------------------------------------------------------------------------------------------------------------------
void Projector3D4Order::currents( double *Jx, double *Jy, double *Jz, Particles &particles, unsigned int ipart, double invgf, int *iold, double *deltaold )
{
    int nparts = particles.size();
    
    // -------------------------------------
    // Variable declaration & initialization
    // -------------------------------------
    
    // (x,y,z) components of the current density for the macro-particle
    double charge_weight = inv_cell_volume * ( double )( particles.charge( ipart ) )*particles.weight( ipart );
    double crx_p = charge_weight*dx_ov_dt;
    double cry_p = charge_weight*dy_ov_dt;
    double crz_p = charge_weight*dz_ov_dt;
    
    // variable declaration
    double xpn, ypn, zpn;
    double delta, delta2, delta3, delta4;
    // arrays used for the Esirkepov projection method
    double Sx0[7], Sx1[7], Sy0[7], Sy1[7], Sz0[7], Sz1[7], DSx[7], DSy[7], DSz[7];
    double tmpJx[7][7], tmpJy[7][7], tmpJz[7][7];
    
    for( unsigned int i=0; i<7; i++ ) {
        Sx1[i] = 0.;
        Sy1[i] = 0.;
        Sz1[i] = 0.;
    }
    for( unsigned int j=0; j<7; j++ )
        for( unsigned int k=0; k<7; k++ ) {
            tmpJx[j][k] = 0.;
        }
    for( unsigned int i=0; i<7; i++ )
        for( unsigned int k=0; k<7; k++ ) {
            tmpJy[i][k] = 0.;
        }
    for( unsigned int i=0; i<7; i++ )
        for( unsigned int j=0; j<7; j++ ) {
            tmpJz[i][j] = 0.;
        }
        
    // --------------------------------------------------------
    // Locate particles & Calculate Esirkepov coef. S, DS and W
    // --------------------------------------------------------
    
    // locate the particle on the primal grid at former time-step & calculate coeff. S0
    delta = deltaold[0*nparts];
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    Sx0[0] = 0.;
    Sx0[1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sx0[2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx0[3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sx0[4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx0[5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sx0[6] = 0.;
    
    delta = deltaold[1*nparts];
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    Sy0[0] = 0.;
    Sy0[1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sy0[2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy0[3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sy0[4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy0[5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sy0[6] = 0.;
    
    delta = deltaold[2*nparts];
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    Sz0[0] = 0.;
    Sz0[1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sz0[2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sz0[3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sz0[4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sz0[5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sz0[6] = 0.;
    
    // locate the particle on the primal grid at current time-step & calculate coeff. S1
    xpn = particles.position( 0, ipart ) * dx_inv_;
    int ip = round( xpn );
    int ipo = iold[0*nparts];
    int ip_m_ipo = ip-ipo-i_domain_begin;
    delta  = xpn - ( double )ip;
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    Sx1[ip_m_ipo+1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sx1[ip_m_ipo+2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx1[ip_m_ipo+3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sx1[ip_m_ipo+4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sx1[ip_m_ipo+5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    
    ypn = particles.position( 1, ipart ) * dy_inv_;
    int jp = round( ypn );
    int jpo = iold[1*nparts];
    int jp_m_jpo = jp-jpo-j_domain_begin;
    delta  = ypn - ( double )jp;
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    Sy1[jp_m_jpo+1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sy1[jp_m_jpo+2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy1[jp_m_jpo+3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sy1[jp_m_jpo+4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sy1[jp_m_jpo+5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    
    zpn = particles.position( 2, ipart ) * dz_inv_;
    int kp = round( zpn );
    int kpo = iold[2*nparts];
    int kp_m_kpo = kp-kpo-k_domain_begin;
    delta  = zpn - ( double )kp;
    delta2 = delta*delta;
    delta3 = delta2*delta;
    delta4 = delta3*delta;
    Sz1[kp_m_kpo+1] = dble_1_ov_384   - dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 - dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    Sz1[kp_m_kpo+2] = dble_19_ov_96   - dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 + dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sz1[kp_m_kpo+3] = dble_115_ov_192 - dble_5_ov_8   * delta2 + dble_1_ov_4  * delta4;
    Sz1[kp_m_kpo+4] = dble_19_ov_96   + dble_11_ov_24 * delta  + dble_1_ov_4  * delta2 - dble_1_ov_6  * delta3 - dble_1_ov_6  * delta4;
    Sz1[kp_m_kpo+5] = dble_1_ov_384   + dble_1_ov_48  * delta  + dble_1_ov_16 * delta2 + dble_1_ov_12 * delta3 + dble_1_ov_24 * delta4;
    
    // computes Esirkepov coefficients
    for( unsigned int i=0; i < 7; i++ ) {
        DSx[i] = Sx1[i] - Sx0[i];
        DSy[i] = Sy1[i] - Sy0[i];
        DSz[i] = Sz1[i] - Sz0[i];
    }
    
    // ---------------------------
    // Calculate the total current
    // ---------------------------
    
    ipo -= 3;   //This minus 3 come from the order 4 scheme, based on a 7 points stencil from -3 to +3.
    // i/j/kpo stored with - i/j/k_domain_begin in Interpolator
    jpo -= 3;
    kpo -= 3;
    
    int iloc, jloc, kloc, linindex;
    
    // Jx^(d,p,p)
    for( unsigned int i=1 ; i<7 ; i++ ) {
        iloc = i+ipo;
        for( unsigned int j=0 ; j<7 ; j++ ) {
            jloc = j+jpo;
            for( unsigned int k=0 ; k<7 ; k++ ) {
                tmpJx[j][k] -= crx_p * DSx[i-1] * ( Sy0[j]*Sz0[k] + 0.5*DSy[j]*Sz0[k] + 0.5*DSz[k]*Sy0[j] + one_third*DSy[j]*DSz[k] );
                kloc = k+kpo;
                linindex = iloc*nprimz*nprimy+jloc*nprimz+kloc;
                Jx [linindex] += tmpJx[j][k]; // iloc = (i+ipo)*nprimy;
            }
        }
    }//i
    
    // Jy^(p,d,p)
    for( unsigned int i=0 ; i<7 ; i++ ) {
        iloc = i+ipo;
        for( unsigned int j=1 ; j<7 ; j++ ) {
            jloc = j+jpo;
            for( unsigned int k=0 ; k<7 ; k++ ) {
                tmpJy[i][k] -= cry_p * DSy[j-1] * ( Sz0[k]*Sx0[i] + 0.5*DSz[k]*Sx0[i] + 0.5*DSx[i]*Sz0[k] + one_third*DSz[k]*DSx[i] );
                kloc = k+kpo;
                linindex = iloc*nprimz*( nprimy+1 )+jloc*nprimz+kloc;
                Jy [linindex] += tmpJy[i][k]; //
            }
        }
    }//i
    
    // Jz^(p,p,d)
    for( unsigned int i=0 ; i<7 ; i++ ) {
        iloc = i+ipo;
        for( unsigned int j=0 ; j<7 ; j++ ) {
            jloc = j+jpo;
            for( unsigned int k=1 ; k<7 ; k++ ) {
                tmpJz[i][j] -= crz_p * DSz[k-1] * ( Sx0[i]*Sy0[j] + 0.5*DSx[i]*Sy0[j] + 0.5*DSy[j]*Sx0[i] + one_third*DSx[i]*DSy[j] );
                kloc = k+kpo;
                linindex = iloc*( nprimz+1 )*nprimy+jloc*( nprimz+1 )+kloc;
                Jz [linindex] += tmpJz[i][j]; //
            }
        }
    }//i
    
    
} // END Project local current densities (Jx, Jy, Jz, sort)