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author | tlatorre <tlatorre@uchicago.edu> | 2018-08-14 10:08:27 -0500 |
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committer | tlatorre <tlatorre@uchicago.edu> | 2018-08-14 10:08:27 -0500 |
commit | 24c8bcfe7f76b20124e2862ea050f815c0f768e7 (patch) | |
tree | e5bdbd638a2c7f38f1c094cc9e95cbdfe05b9481 /likelihood.c | |
parent | 0b7f199c0d93074484ea580504485a32dc29f5e2 (diff) | |
download | sddm-24c8bcfe7f76b20124e2862ea050f815c0f768e7.tar.gz sddm-24c8bcfe7f76b20124e2862ea050f815c0f768e7.tar.bz2 sddm-24c8bcfe7f76b20124e2862ea050f815c0f768e7.zip |
move everything to src directory
Diffstat (limited to 'likelihood.c')
-rw-r--r-- | likelihood.c | 274 |
1 files changed, 0 insertions, 274 deletions
diff --git a/likelihood.c b/likelihood.c deleted file mode 100644 index 98a4ad7..0000000 --- a/likelihood.c +++ /dev/null @@ -1,274 +0,0 @@ -#include "likelihood.h" -#include <stdlib.h> /* for size_t */ -#include "pmt.h" -#include <gsl/gsl_integration.h> -#include "muon.h" -#include "misc.h" -#include <gsl/gsl_sf_gamma.h> -#include "sno.h" -#include "vector.h" -#include "event.h" -#include "optics.h" -#include "sno_charge.h" -#include "pdg.h" - -double F(double t, double mu_noise, double mu_indirect, double *mu_direct, size_t n, double *ts, double tmean, double sigma) -{ - /* Returns the CDF for the time distribution of photons at time `t`. */ - size_t i; - double p, mu_total; - - p = mu_noise*t/GTVALID + mu_indirect*(pow(sigma,2)*norm(tmean,t,sigma) + (t-tmean)*norm_cdf(t,tmean,sigma))/(GTVALID-tmean); - - mu_total = mu_noise + mu_indirect; - for (i = 0; i < n; i++) { - p += mu_direct[i]*norm_cdf(t,ts[i],sigma); - mu_total += mu_direct[i]; - } - - return p/mu_total; -} - -double f(double t, double mu_noise, double mu_indirect, double *mu_direct, size_t n, double *ts, double tmean, double sigma) -{ - /* Returns the probability that a photon is detected at time `t`. - * - * The probability distribution is the sum of three different components: - * dark noise, indirect light, and direct light. The dark noise is assumed - * to be constant in time. The direct light is assumed to be a delta - * function around the times `ts`, where each element of `ts` comes from a - * different particle. This assumption is probably valid for particles - * like muons which don't scatter much, and the hope is that it is *good - * enough* for electrons too. The probability distribution for indirect - * light is assumed to be a step function past some time `tmean`. - * - * The probability returned is calculated by taking the sum of these three - * components and convolving it with a gaussian with standard deviation - * `sigma` which should typically be the PMT transit time spread. */ - size_t i; - double p, mu_total; - - p = mu_noise/GTVALID + mu_indirect*norm_cdf(t,tmean,sigma)/(GTVALID-tmean); - - mu_total = mu_noise + mu_indirect; - for (i = 0; i < n; i++) { - p += mu_direct[i]*norm(t,ts[i],sigma); - mu_total += mu_direct[i]; - } - - return p/mu_total; -} - -double log_pt(double t, size_t n, double mu_noise, double mu_indirect, double *mu_direct, size_t n2, double *ts, double tmean, double sigma) -{ - /* Returns the first order statistic for observing a PMT hit at time `t` - * given `n` hits. - * - * The first order statistic is computed from the probability distribution - * above. It's not obvious whether one should take the first order - * statistic before or after convolving with the PMT transit time spread. - * Since at least some of the transit time spread in SNO comes from the - * different transit times across the face of the PMT, it seems better to - * convolve first which is what we do here. In addition, the problem is not - * analytically tractable if you do things the other way around. */ - return log(n) + (n-1)*log1p(-F(t,mu_noise,mu_indirect,mu_direct,n2,ts,tmean,sigma)) + log(f(t,mu_noise,mu_indirect,mu_direct,n2,ts,tmean,sigma)); -} - -static double gsl_muon_time(double x, void *params) -{ - double *params2 = (double *) params; - double T0 = params2[0]; - double pos0[3], dir[3], pos[3], pmt_dir[3]; - int i; - double t; - i = (int) params2[1]; - pos0[0] = params2[2]; - pos0[1] = params2[3]; - pos0[2] = params2[4]; - dir[0] = params2[5]; - dir[1] = params2[6]; - dir[2] = params2[7]; - - pos[0] = pos0[0] + dir[0]*x; - pos[1] = pos0[1] + dir[1]*x; - pos[2] = pos0[2] + dir[2]*x; - - SUB(pmt_dir,pmts[i].pos,pos); - - double distance = NORM(pmt_dir); - - /* FIXME: I just calculate delta assuming 400 nm light. */ - double wavelength0 = 400.0; - double n = get_index(HEAVY_WATER_DENSITY, wavelength0, 10.0); - - t = x/SPEED_OF_LIGHT + distance*n/SPEED_OF_LIGHT; - - return t*get_expected_charge(x, get_T(T0, x, HEAVY_WATER_DENSITY), pos, dir, pmts[i].pos, pmts[i].normal, PMT_RADIUS); -} - -static double gsl_muon_charge(double x, void *params) -{ - double *params2 = (double *) params; - double T0 = params2[0]; - double pos0[3], dir[3], pos[3]; - int i; - i = (int) params2[1]; - pos0[0] = params2[2]; - pos0[1] = params2[3]; - pos0[2] = params2[4]; - dir[0] = params2[5]; - dir[1] = params2[6]; - dir[2] = params2[7]; - - pos[0] = pos0[0] + dir[0]*x; - pos[1] = pos0[1] + dir[1]*x; - pos[2] = pos0[2] + dir[2]*x; - - return get_expected_charge(x, get_T(T0, x, HEAVY_WATER_DENSITY), pos, dir, pmts[i].pos, pmts[i].normal, PMT_RADIUS); -} - -double nll_muon(event *ev, double T, double *pos, double *dir, double t0) -{ - size_t i, j; - double params[8]; - double total_charge; - double logp[MAX_PE], nll, range, pmt_dir[3], R, x, cos_theta, theta, theta_cerenkov; - double tmean = 0.0; - int npmt = 0; - - double mu_direct[MAX_PMTS]; - double ts[MAX_PMTS]; - double mu[MAX_PMTS]; - double mu_noise, mu_indirect; - - gsl_integration_cquad_workspace *w = gsl_integration_cquad_workspace_alloc(100); - double result, error; - - size_t nevals; - - gsl_function F; - F.params = ¶ms; - - range = get_range(T, HEAVY_WATER_DENSITY); - - total_charge = 0.0; - npmt = 0; - for (i = 0; i < MAX_PMTS; i++) { - if (ev->pmt_hits[i].flags || (pmts[i].pmt_type != PMT_NORMAL && pmts[i].pmt_type != PMT_OWL)) continue; - - params[0] = T; - params[1] = i; - params[2] = pos[0]; - params[3] = pos[1]; - params[4] = pos[2]; - params[5] = dir[0]; - params[6] = dir[1]; - params[7] = dir[2]; - - /* First, we try to compute the distance along the track where the - * PMT is at the Cerenkov angle. The reason for this is because for - * heavy particles like muons which don't scatter much, the probability - * distribution for getting a photon hit along the track looks kind of - * like a delta function, i.e. the PMT is only hit over a very narrow - * window when the angle between the track direction and the PMT is - * *very* close to the Cerenkov angle (it's not a perfect delta - * function since there is some width due to dispersion). In this case, - * it's possible that the numerical integration completely skips over - * the delta function and so predicts an expected charge of 0. To fix - * this, we compute the integral in two steps, one up to the point - * along the track where the PMT is at the Cerenkov angle and another - * from that point to the end of the track. Since the integration - * routine always samples points near the beginning and end of the - * integral, this allows the routine to correctly compute that the - * integral is non zero. */ - - SUB(pmt_dir,pmts[i].pos,pos); - /* Compute the distance to the PMT. */ - R = NORM(pmt_dir); - normalize(pmt_dir); - - /* Calculate the cosine of the angle between the track direction and the - * vector to the PMT. */ - cos_theta = DOT(dir,pmt_dir); - /* Compute the angle between the track direction and the PMT. */ - theta = acos(cos_theta); - /* Compute the Cerenkov angle. Note that this isn't entirely correct - * since we aren't including the factor of beta, but since the point is - * just to split up the integral, we only need to find a point along - * the track close enough such that the integral isn't completely zero. - */ - theta_cerenkov = acos(1/get_index(WATER_DENSITY,400.0,10.0)); - - /* Now, we compute the distance along the track where the PMT is at the - * Cerenkov angle. */ - x = R*sin(theta_cerenkov-theta)/sin(theta_cerenkov); - - if (x > 0 && x < range) { - /* Split up the integral at the point where the PMT is at the - * Cerenkov angle. */ - F.function = &gsl_muon_charge; - gsl_integration_cquad(&F, 0, x, 0, 1e-2, w, &result, &error, &nevals); - mu_direct[i] = result; - gsl_integration_cquad(&F, x, range, 0, 1e-2, w, &result, &error, &nevals); - mu_direct[i] += result; - - F.function = &gsl_muon_time; - gsl_integration_cquad(&F, 0, x, 0, 1e-2, w, &result, &error, &nevals); - ts[i] = result; - gsl_integration_cquad(&F, x, range, 0, 1e-2, w, &result, &error, &nevals); - ts[i] += result; - } else { - F.function = &gsl_muon_charge; - gsl_integration_cquad(&F, 0, range, 0, 1e-2, w, &result, &error, &nevals); - mu_direct[i] = result; - - F.function = &gsl_muon_time; - gsl_integration_cquad(&F, 0, range, 0, 1e-2, w, &result, &error, &nevals); - ts[i] = result; - } - - total_charge += mu_direct[i]; - - if (mu_direct[i] > 0.001) { - ts[i] /= mu_direct[i]; - ts[i] += t0; - tmean += ts[i]; - npmt += 1; - } else { - ts[i] = 0.0; - } - } - - tmean /= npmt; - - gsl_integration_cquad_workspace_free(w); - - mu_noise = DARK_RATE*GTVALID*1e-9; - mu_indirect = total_charge/CHARGE_FRACTION; - - for (i = 0; i < MAX_PMTS; i++) { - if (ev->pmt_hits[i].flags || (pmts[i].pmt_type != PMT_NORMAL && pmts[i].pmt_type != PMT_OWL)) continue; - mu[i] = mu_direct[i] + mu_indirect + mu_noise; - } - - nll = 0; - for (i = 0; i < MAX_PMTS; i++) { - if (ev->pmt_hits[i].flags || (pmts[i].pmt_type != PMT_NORMAL && pmts[i].pmt_type != PMT_OWL)) continue; - - if (ev->pmt_hits[i].hit) { - logp[0] = -INFINITY; - for (j = 1; j < MAX_PE; j++) { - logp[j] = log(pq(ev->pmt_hits[i].qhs,j)) - mu[i] + j*log(mu[i]) - gsl_sf_lnfact(j) + log_pt(ev->pmt_hits[i].t, j, mu_noise, mu_indirect, &mu_direct[i], 1, &ts[i], tmean, 1.5); - } - nll -= logsumexp(logp, sizeof(logp)/sizeof(double)); - } else { - logp[0] = -mu[i]; - for (j = 1; j < MAX_PE; j++) { - logp[j] = log(get_pmiss(j)) - mu[i] + j*log(mu[i]) - gsl_sf_lnfact(j); - } - nll -= logsumexp(logp, sizeof(logp)/sizeof(double)); - } - } - - return nll; -} |