double dtau_e_dz(double z, void *params){
float xH, xi;
int i=1;
tau_e_params p = *(tau_e_params *)params;
if ((p.len == 0) || !(p.z))
return (1+z)*(1+z)*drdz(z);
else{
// find where we are in the redshift array
if (p.z[0]>z) // ionization fraction is 1 prior to start of array
return (1+z)*(1+z)*drdz(z);
while ( (i < p.len) && (p.z[i] < z) ) {i++;}
if (i == p.len)
return 0;
// linearly interpolate in redshift
xH = p.xH[i-1] + (p.xH[i] - p.xH[i-1])/(p.z[i] - p.z[i-1]) * (z - p.z[i-1]);
/*
fprintf(stderr, "in taue: Interpolating between xH(%f)=%f and xH(%f)=%f to obtain xH(%f)=%f\n",
p.z[i-1], p.xH[i-1], p.z[i], p.xH[i], z, xH);
*/
xi = 1.0-xH;
if (xi<0){
fprintf(stderr, "in taue: funny buisness xi=%e, changing to 0\n", xi);
xi=0;
}
if (xi>1){
fprintf(stderr, "in taue: funny buisness xi=%e, changing to 1\n", xi);
xi=1;
}
return xi*(1+z)*(1+z)*drdz(z);
}
}
int main(int argc, char * argv[]) {
int i,nz,ind;
double z,dz=0.01,zv[1000],xH[1000];
double nH0,nHe0,ne0,tau,tau2,ddz;
FILE *fid;
char fname[300];
/* Check for correct number of parameters*/
if (argc != 2) {
printf("Usage : opdepth base_dir (for simulation)\n");
exit(0);
}
get_Simfast21_params(argv[1]);
sprintf(fname,"%s/Output_text_files/zsim.txt",argv[1]);
if((fid = fopen(fname,"r"))==NULL) {
printf("Error opening file:%s\n",fname);
exit(1);
}
i=0;
while(fscanf(fid,"%lf",&(zv[i]))==1) i++;
nz=i;
printf("Number of lines: %d\n",nz);
fclose(fid);
sprintf(fname, "%s/Output_text_files/x_HI_eff%.2lf_N%ld_L%.0f.dat",argv[1],global_eff,global_N_smooth,global_L/global_hubble);
if((fid = fopen(fname,"r"))==NULL) {
printf("Error opening file:%s\n",fname);
exit(1);
}
i=0;
while(fscanf(fid,"%lf",&(xH[i]))==1) i++;
fclose(fid);
if(i!=nz) {printf("Error!\n");exit(1);}
nH0=(1.-YHe)*(global_rho_b*Msun/pow(Mpc2m*100./global_hubble,3))/mH; /* cm^-3 */
nHe0=(YHe)*(global_rho_b*Msun/pow(Mpc2m*100./global_hubble,3))/mHe; /* cm^-3 */
ne0=nH0+nHe0;
tau=0.;
for(z=0.;z<zv[nz-1];z+=dz) {
tau+=(1.+z)*(1.+z)*drdz(z);
}
tau=tau*dz*ne0*sigt*Mpc2m/global_hubble*100.;
printf("Full ionization part: %E\n",tau);
ddz=(zv[0]-zv[nz-1])/(nz-1);
tau2=0.;
while(z<=zv[0]) {
ind=(int)round((z-zv[nz-1])/ddz);
if(ind>nz-1 || ind <0) printf("Error - ind: %d\n",ind);
ind=nz-1-ind;
tau2+=(1.+z)*(1.+z)*drdz(z)*(1.-xH[ind]);
z+=dz;
}
tau2=tau2*dz*ne0*sigt*Mpc2m/global_hubble*100.;
printf("xHII ionization part: %E\n",tau2);
printf("Total: %E\n",tau+tau2);
exit(0);
}
/* Return the comoving distance (in cm) traveled by photon (i.e. length of a null geodesic) from zsource to z */
double dcom_dz(double z, void *params){
return drdz(z);
}