public int Reshape(MemoryCollection col)
{
int nNum = col.Count;
int nChannels = col[0].Data.Channels;
int nHeight = col[0].Data.Height;
int nWidth = col[0].Data.Height;
int nActionProbs = 1;
int nFound = 0;
for (int i = 0; i < m_net.output_blobs.Count; i++)
{
if (m_net.output_blobs[i].type != Blob <T> .BLOB_TYPE.LOSS)
{
int nCh = m_net.output_blobs[i].channels;
nActionProbs = Math.Max(nCh, nActionProbs);
nFound++;
}
}
if (nFound == 0)
{
throw new Exception("Could not find a non-loss output! Your model should output the loss and the action probabilities.");
}
m_blobDiscountedR.Reshape(nNum, nActionProbs, 1, 1);
m_blobPolicyGradient.Reshape(nNum, nActionProbs, 1, 1);
m_blobActionOneHot.Reshape(nNum, nActionProbs, 1, 1);
m_blobDiscountedR1.Reshape(nNum, nActionProbs, 1, 1);
m_blobPolicyGradient1.Reshape(nNum, nActionProbs, 1, 1);
m_blobActionOneHot1.Reshape(nNum, nActionProbs, 1, 1);
m_blobLoss.Reshape(1, 1, 1, 1);
return(nActionProbs);
}
/// <summary>
/// The Run method provides the main 'actor' loop that performs the following steps:
/// 1.) get state
/// 2.) build experience
/// 3.) create policy gradients
/// 4.) train on experiences
/// </summary>
/// <param name="phase">Specifies the phae.</param>
/// <param name="nN">Specifies the number of iterations (based on the ITERATION_TYPE) to run, or -1 to ignore.</param>
/// <param name="type">Specifies the iteration type (default = ITERATION).</param>
/// <param name="step">Specifies the training step to take, if any. This is only used when debugging.</param>
public void Run(Phase phase, int nN, ITERATOR_TYPE type, TRAIN_STEP step)
{
MemoryCollection m_rgMemory = new MemoryCollection();
double? dfRunningReward = null;
double dfEpisodeReward = 0;
int nEpisode = 0;
int nIteration = 0;
StateBase s = getData(phase, -1);
while (!m_brain.Cancel.WaitOne(0) && !isAtIteration(nN, type, nIteration, nEpisode))
{
// Preprocess the observation.
SimpleDatum x = m_brain.Preprocess(s, m_bUseRawInput);
// Forward the policy network and sample an action.
float[] rgfAprob;
int action = m_brain.act(x, s.Clip, out rgfAprob);
if (step == TRAIN_STEP.FORWARD)
{
return;
}
// Take the next step using the action
StateBase s_ = getData(phase, action);
dfEpisodeReward += s_.Reward;
if (phase == Phase.TRAIN)
{
// Build up episode memory, using reward for taking the action.
m_rgMemory.Add(new MemoryItem(s, x, action, rgfAprob, (float)s_.Reward));
// An episode has finished.
if (s_.Done)
{
nEpisode++;
nIteration++;
m_brain.Reshape(m_rgMemory);
// Compute the discounted reward (backwards through time)
float[] rgDiscountedR = m_rgMemory.GetDiscountedRewards(m_fGamma, m_bAllowDiscountReset);
// Rewards are standardized when set to be unit normal (helps control the gradient estimator variance)
m_brain.SetDiscountedR(rgDiscountedR);
// Get the action probabilities.
float[] rgfAprobSet = m_rgMemory.GetActionProbabilities();
// The action probabilities are used to calculate the initial gradient within the loss function.
m_brain.SetActionProbabilities(rgfAprobSet);
// Get the action one-hot vectors. When using Softmax, this contains the one-hot vector containing
// each action set (e.g. 3 actions with action 0 set would return a vector <1,0,0>).
// When using a binary probability (e.g. with Sigmoid), the each action set only contains a
// single element which is set to the action value itself (e.g. 0 for action '0' and 1 for action '1')
float[] rgfAonehotSet = m_rgMemory.GetActionOneHotVectors();
m_brain.SetActionOneHotVectors(rgfAonehotSet);
// Train for one iteration, which triggers the loss function.
List <Datum> rgData = m_rgMemory.GetData();
List <Datum> rgClip = m_rgMemory.GetClip();
m_brain.SetData(rgData, rgClip);
m_brain.Train(nIteration, step);
// Update reward running
if (!dfRunningReward.HasValue)
{
dfRunningReward = dfEpisodeReward;
}
else
{
dfRunningReward = dfRunningReward * 0.99 + dfEpisodeReward * 0.01;
}
updateStatus(nIteration, nEpisode, dfEpisodeReward, dfRunningReward.Value);
dfEpisodeReward = 0;
s = getData(phase, -1);
m_rgMemory.Clear();
if (step != TRAIN_STEP.NONE)
{
return;
}
}
else
{
s = s_;
}
}
else
{
if (s_.Done)
{
nEpisode++;
// Update reward running
if (!dfRunningReward.HasValue)
{
dfRunningReward = dfEpisodeReward;
}
else
{
dfRunningReward = dfRunningReward * 0.99 + dfEpisodeReward * 0.01;
}
updateStatus(nIteration, nEpisode, dfEpisodeReward, dfRunningReward.Value);
dfEpisodeReward = 0;
s = getData(phase, -1);
}
else
{
s = s_;
}
nIteration++;
}
}
}
