static void lb_calc_local_moments(double *f) {
int i;
double *m = f + lblattice.halo_grid_volume*lbmodel.n_vel;
double rho, p, dp, d2p;
for (i=0; i<lbmodel.n_vel; ++i) {
m[i] = 0.0;
}
for (i=0; i<lbmodel.n_vel; ++i) {
m[0] += f[i];
m[1] += f[i]*lbmodel.c[i][0];
m[2] += f[i]*lbmodel.c[i][1];
m[3] += f[i]*lbmodel.c[i][0]*lbmodel.c[i][0];
m[4] += f[i]*lbmodel.c[i][1]*lbmodel.c[i][1];
m[5] += f[i]*lbmodel.c[i][0]*lbmodel.c[i][1];
}
/* evaluate equation of state */
rho = m[0];
p = rho*eq_state(rho);
dp = derP(rho);
d2p = der2P(rho);
LB_Moments *lbmom = (LB_Moments *)m;
/* pressure and derivatives */
lbmom->p = p;
lbmom->dp = dp;
lbmom->pmrdp = p - rho*dp;
lbmom->rd2p = rho*d2p;
/* force */
lbmom->force[0] = 0.0;
lbmom->force[1] = 0.0;
/* velocity */
lbmom->u[0] = m[1]/m[0];
lbmom->u[1] = m[2]/m[0];
/* correction current */
//lbmom->jcorr[0] = 0.0;
//lbmom->jcorr[1] = 0.0;
}
// Derivative of the error function
static double dererrh(int n, double *c, double y, double epsilon) {
double p = P(n, c, y, epsilon), dp = derP(n, c, y, epsilon);
return -0.5 * p / sqrt(y) - sqrt(y) * dp;
}
