public static Uncertain <T[]> MarkovModel <T>(this Uncertain <T[]> observations, Uncertain <T> init, Func <T, Uncertain <T> > transition, Func <T, Uncertain <T> > emission) where T : IEquatable <T>
{
Func <IEnumerable <T>, Uncertain <T[]> > RunOne = obs =>
{
var initlst = from prior in init
select FunctionalList.Cons(prior, FunctionalList.Empty <T>());
return(obs.Aggregate <T, Uncertain <FunctionalList <T> >, Uncertain <T[]> >(
initlst,
(list, obs_i) =>
{
var program = from head in list
let state = head.Head
from next in transition(state)
from emit in emission(next)
where obs_i.Equals(emit)
select FunctionalList.Cons(next, head);
return program;
},
uncertainlst =>
{
return from sample in uncertainlst
select sample.Reverse().Skip(1) /* skip prior */.ToArray();
}));
};
return(from obs in observations
from result in RunOne(obs)
select result);
//Uncertain < T[] > output = observations.Aggregate<Uncertain<T>, Uncertain<FunctionalList<T>>, Uncertain<T[]>>(
// FunctionalList.Empty<T>(),
// (i, j) =>
// {
// return from lst in i
// from sample in j
// select FunctionalList.Cons(sample, lst);
// },
// uncertainlst =>
// {
// return from sample in uncertainlst
// select sample.Reverse().ToArray();
// });
//return output;
}
public static Uncertain <T[]> USeq <T>(this IEnumerable <Uncertain <T> > source, int num)
{
Uncertain <T[]> output = source.Take(num).Aggregate <Uncertain <T>, Uncertain <FunctionalList <T> >, Uncertain <T[]> >(
FunctionalList.Empty <T>(),
(i, j) =>
{
return(from lst in i
from sample in j
select FunctionalList.Cons(sample, lst));
},
uncertainlst =>
{
return(from sample in uncertainlst
select sample.Reverse().ToArray());
});
return(output);
}
public static Uncertain <R[]> USeq2 <T, R>(this IEnumerable <Uncertain <T> > source, Func <T[], R[]> selector)
{
Uncertain <R[]> output = source.Aggregate <Uncertain <T>, Uncertain <FunctionalList <T> >, Uncertain <R[]> >(
FunctionalList.Empty <T>(),
(i, j) =>
{
return(from lst in i
from sample in j
select FunctionalList.Cons(sample, lst));
},
uncertainlst =>
{
return(from sample in uncertainlst
let vec = sample.Reverse().ToArray()
select selector(vec));
});
return(output);
}
IEnumerator IEnumerable.GetEnumerator()
{
return(FunctionalList.Helper <T>(this).GetEnumerator());
}
public IEnumerator <T> GetEnumerator()
{
return(FunctionalList.Helper <T>(this).GetEnumerator());
}
// Creates a new list containe value and a reference to tail
public FunctionalList(T head, FunctionalList <T> tail)
{
IsEmpty = false;
Head = head;
Tail = tail;
}
