Ejemplo n.º 1
0
        internal CPT PointWiseProduct(CPT other)
        {
            IEnumerable <RandomVariable> commonVars = this.vars.Intersect(other.vars);
            HashSet <RandomVariable>     rightVars  = new HashSet <RandomVariable>(other.vars);

            rightVars.ExceptWith(commonVars);

            int[] commVarsIndicesInLeft  = commonVars.Select <RandomVariable, int>(v => keyPosMap[v]).ToArray();
            int[] commVarsIndicesInRight = commonVars.Select <RandomVariable, int>(v => other.keyPosMap[v]).ToArray();

            List <RandomVariable> varsInResultCPT   = new List <RandomVariable>(this.vars);
            List <RandomVariable> rightVarsInResult = new List <RandomVariable>(other.vars);

            rightVarsInResult.RemoveAll(v => commonVars.Contains(v));
            varsInResultCPT.AddRange(rightVarsInResult);

            Dictionary <RandomVariable, int> newKeyPosMap = new Dictionary <RandomVariable, int>();

            for (int i = 0; i < varsInResultCPT.Count(); i++)
            {
                newKeyPosMap.Add(varsInResultCPT[i], i);
            }

            int newCptSize = varsInResultCPT.Aggregate <RandomVariable, int>(1, (acc, v) => acc * v.tokens.Length);

            CptEntry[] newCptEntries = new CptEntry[newCptSize];

            Dictionary <CptKey, List <CptEntry> > mapping = new Dictionary <CptKey, List <CptEntry> >();

            CategoriseEntries(other, commVarsIndicesInRight, mapping);

            int cptIndex = 0;

            foreach (CptEntry leftEntry in this.cpt)
            {
                CptKey          key   = leftEntry.key.Extract(commVarsIndicesInLeft);
                List <CptEntry> right = mapping[key];
                foreach (CptEntry rightEntry in right)
                {
                    CptKey newKey = leftEntry.key.Concat(rightEntry.key.Remove(commVarsIndicesInRight));
                    newCptEntries[cptIndex] = new CptEntry(newKey, leftEntry.value * rightEntry.value);
                    cptIndex++;
                }
            }

            return(new CPT(varsInResultCPT.ToArray(), newKeyPosMap, newCptEntries));
        }
Ejemplo n.º 2
0
        internal CPT(RandomVariable[] vars, double[] values)
        {
            this.vars      = vars;
            this.keyPosMap = new Dictionary <RandomVariable, int>();
            this.cpt       = new CptEntry[values.Length];

            for (int i = 0; i < vars.Length; i++)
            {
                keyPosMap.Add(vars[i], i);
            }

            CptKey[] keys = Enumerable.Range(1, values.Length).Select(_ => new CptKey(vars.Length)).ToArray();
            SetKeys(new ArraySegment <CptKey>(keys), new ArraySegment <RandomVariable>(vars));

            for (int i = 0; i < cpt.Length; i++)
            {
                cpt[i] = new CptEntry(keys[i], values[i]);
            }
        }