From 0acc92a0eecf04a2c429f6f7685bfcaa68c7ec3a Mon Sep 17 00:00:00 2001
From: Chris Dyer <cdyer@cs.cmu.edu>
Date: Tue, 11 Oct 2011 12:06:32 +0100
Subject: check in some experimental particle filtering code, some gitignore
 fixes

---
 gi/pf/base_measures.cc | 112 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 gi/pf/base_measures.cc

(limited to 'gi/pf/base_measures.cc')

diff --git a/gi/pf/base_measures.cc b/gi/pf/base_measures.cc
new file mode 100644
index 00000000..f8ddfd32
--- /dev/null
+++ b/gi/pf/base_measures.cc
@@ -0,0 +1,112 @@
+#include "base_measures.h"
+
+#include <iostream>
+
+#include "filelib.h"
+
+using namespace std;
+
+void Model1::LoadModel1(const string& fname) {
+  cerr << "Loading Model 1 parameters from " << fname << " ..." << endl;
+  ReadFile rf(fname);
+  istream& in = *rf.stream();
+  string line;
+  unsigned lc = 0;
+  while(getline(in, line)) {
+    ++lc;
+    int cur = 0;
+    int start = 0;
+    while(cur < line.size() && line[cur] != ' ') { ++cur; }
+    assert(cur != line.size());
+    line[cur] = 0;
+    const WordID src = TD::Convert(&line[0]);
+    ++cur;
+    start = cur;
+    while(cur < line.size() && line[cur] != ' ') { ++cur; }
+    assert(cur != line.size());
+    line[cur] = 0;
+    WordID trg = TD::Convert(&line[start]);
+    const double logprob = strtod(&line[cur + 1], NULL);
+    if (src >= ttable.size()) ttable.resize(src + 1);
+    ttable[src][trg].logeq(logprob);
+  }
+  cerr << "  read " << lc << " parameters.\n";
+}
+
+prob_t PhraseConditionalBase::p0(const vector<WordID>& vsrc,
+                                 const vector<WordID>& vtrg,
+                                 int start_src, int start_trg) const {
+  const int flen = vsrc.size() - start_src;
+  const int elen = vtrg.size() - start_trg;
+  prob_t uniform_src_alignment; uniform_src_alignment.logeq(-log(flen + 1));
+  prob_t p;
+  p.logeq(log_poisson(elen, flen + 0.01));       // elen | flen          ~Pois(flen + 0.01)
+  for (int i = 0; i < elen; ++i) {               // for each position i in e-RHS
+    const WordID trg = vtrg[i + start_trg];
+    prob_t tp = prob_t::Zero();
+    for (int j = -1; j < flen; ++j) {
+      const WordID src = j < 0 ? 0 : vsrc[j + start_src];
+      tp += kM1MIXTURE * model1(src, trg);
+      tp += kUNIFORM_MIXTURE * kUNIFORM_TARGET;
+    }
+    tp *= uniform_src_alignment;                 //     draw a_i         ~uniform
+    p *= tp;                                     //     draw e_i         ~Model1(f_a_i) / uniform
+  }
+  if (p.is_0()) {
+    cerr << "Zero! " << vsrc << "\nTRG=" << vtrg << endl;
+    abort();
+  }
+  return p;
+}
+
+prob_t PhraseJointBase::p0(const vector<WordID>& vsrc,
+                           const vector<WordID>& vtrg,
+                           int start_src, int start_trg) const {
+  const int flen = vsrc.size() - start_src;
+  const int elen = vtrg.size() - start_trg;
+  prob_t uniform_src_alignment; uniform_src_alignment.logeq(-log(flen + 1));
+  prob_t p;
+  p.logeq(log_poisson(flen, 1.0));               // flen                 ~Pois(1)
+                                                 // elen | flen          ~Pois(flen + 0.01)
+  prob_t ptrglen; ptrglen.logeq(log_poisson(elen, flen + 0.01));
+  p *= ptrglen;
+  p *= kUNIFORM_SOURCE.pow(flen);                // each f in F ~Uniform
+  for (int i = 0; i < elen; ++i) {               // for each position i in E
+    const WordID trg = vtrg[i + start_trg];
+    prob_t tp = prob_t::Zero();
+    for (int j = -1; j < flen; ++j) {
+      const WordID src = j < 0 ? 0 : vsrc[j + start_src];
+      tp += kM1MIXTURE * model1(src, trg);
+      tp += kUNIFORM_MIXTURE * kUNIFORM_TARGET;
+    }
+    tp *= uniform_src_alignment;                 //     draw a_i         ~uniform
+    p *= tp;                                     //     draw e_i         ~Model1(f_a_i) / uniform
+  }
+  if (p.is_0()) {
+    cerr << "Zero! " << vsrc << "\nTRG=" << vtrg << endl;
+    abort();
+  }
+  return p;
+}
+
+JumpBase::JumpBase() : p(200) {
+  for (unsigned src_len = 1; src_len < 200; ++src_len) {
+    map<int, prob_t>& cpd = p[src_len];
+    int min_jump = 1 - src_len;
+    int max_jump = src_len;
+    prob_t z;
+    for (int j = min_jump; j <= max_jump; ++j) {
+      prob_t& cp = cpd[j];
+      if (j < 0)
+        cp.logeq(log_poisson(1.5-j, 1));
+      else if (j > 0)
+        cp.logeq(log_poisson(j, 1));
+      cp.poweq(0.2);
+      z += cp;
+    }
+    for (int j = min_jump; j <= max_jump; ++j) {
+      cpd[j] /= z;
+    }
+  }
+}
+
-- 
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