/// <param name="actn">order quantity</param>
public QTableKey1(QuantityLifeState state, int actn)
{
State = state;
Action = actn;
}
public static void Start()
{
var randm = new Random(DateTime.UtcNow.Millisecond);
int life_rem = 0;
for (int i = 0; i < 20; i++)
{
var p = new Product();
ProductsOnHand.Add(p);
life_rem += p.LifeRemaining;
}
int ep = 0;
var itr = MathFunctions.GetDemand(a, b, new Random(DateTime.UtcNow.Millisecond)).GetEnumerator();
var actual_demand = itr.Current;
while (ep < Episodes)
{
double ep_reward = 0;
double reward = 0.0;
itr.MoveNext();
var next_demand = itr.Current;
for (int step = 0; step < MaxStepPerEpisode; step++)
{
// recieve the arrived products that was ordered previously
for (int i = OrdersNotArrived.Count - 1; i >= 0; i--)
{
if (OrdersNotArrived[i].RemainingDaysToArrive == 0)
{
var n_new_product = OrdersNotArrived[i].Quantity;
for (int j = 0; j < n_new_product; j++)
{
var prdct = new Product();
prdct.LifeRemaining -= Order.LeadTime;
ProductsOnHand.Add(prdct);
}
OrdersNotArrived.RemoveAt(i);
}
}
// calculate shortage
int Ts = Math.Max(0, actual_demand - ProductsOnHand.Count);
reward += Ts * ShortageCost;
// remove the products consumed by customers
if (ProductsOnHand.Count > 0)
{
for (int i = 0; i < actual_demand; i++)
{
ProductsOnHand.RemoveAt(0);
reward += SalePrice;
if (ProductsOnHand.Count == 0)
{
break;
}
}
}
// discard outdated product and calculate outage amount
int To = 0;
life_rem = 0;
for (int i = ProductsOnHand.Count - 1; i >= 0; i--)
{
ProductsOnHand[i].LifeRemaining--;
if (ProductsOnHand[i].LifeRemaining <= 0)
{
To++;
ProductsOnHand.RemoveAt(i);
}
else
{
life_rem += ProductsOnHand[i].LifeRemaining;
}
}
reward += To * OutageCost;
ep_reward += reward;
if (ep_reward > 800)
{
break;
}
// determine order quantity
int oq, next_oq;
int total_product_count = ProductsOnHand.Count + OrdersNotArrived.Sum(o => o.Quantity);
if (randm.NextDouble() < Epsilon) // explore
{
oq = OrderQuantities[randm.Next(OrderQuantities.Length)];
}
else // exploit
{
oq = Table1.GetMaxOrderQuantityForState(total_product_count, life_rem, OrderQuantities.First(), OrderQuantities.Last());
}
// mustn't exceed inventory capacity
if (total_product_count + oq >= InventoryPositionCount_S1)
{
oq = InventoryPositionCount_S1 - 1 - total_product_count;
}
OrdersNotArrived.Add(new Order(oq));
reward = oq * OrderingCost;
for (int i = 0; i < OrdersNotArrived.Count; i++)
{
life_rem += L - (Order.LeadTime - OrdersNotArrived[i].RemainingDaysToArrive);
OrdersNotArrived[i].RemainingDaysToArrive--;
}
//double reward = -To * co - Ts * cs;
//Console.Write(reward.ToString("N2") + ", ");
//if (ep % 20 == 0)
// Console.WriteLine();
// calculate max q(s',a')
// quantity in next round = on hand inventory + orders in transit - next day demand
total_product_count = ProductsOnHand.Count + OrdersNotArrived.Sum(o => o.Quantity);
int qntity_next_round = total_product_count - next_demand;
next_oq = Table1.GetMaxOrderQuantityForState(total_product_count, life_rem, OrderQuantities.First(), OrderQuantities.Last());
// update q table
var state = new QuantityLifeState(total_product_count, life_rem);
var sa_pair = new QTableKey1(state, oq);
Table1[sa_pair] = (1 - LearningRate) * Table1[sa_pair] + LearningRate * (reward + FutureDiscount * next_oq);
actual_demand = next_demand;
}
EpisodeRewards[ep] = ep_reward;
Console.WriteLine(ep_reward);
ep_reward = 0;
Epsilon *= EpsilonDecay;
ep++;
}
}