private void Learn()
{
//Copy eval net to target net after `replace_target_iteration` iterations
if (learn_step % replace_target_iteration == 0)
{
network_target.SetWeightsData(network_eval.GetWeightsData());
log.Add("Replacing `target net` with `eval net`");
}
//Get batch from memory
int[] batch_index = CreateMemoryBatch();
if (batch_index.Length == 0)
{
return;
}
//Compute network error
for (int i = 0; i < batch_index.Length; i++)
{
//Compute `q_eval` and `q_target`
float[] q_target = network_target.Compute(network_memory[batch_index[i]].next_state);
float[] q_eval = network_eval.Compute(network_memory[batch_index[i]].current_state);
//Compute reward
float reward = network_memory[batch_index[i]].reward;
//Add reward and reward decay
int max_q_target = 0;
for (int j = 0; j < q_target.Length; j++)
{
if (q_target[max_q_target] < q_target[j])
{
max_q_target = j;
}
}
q_target[max_q_target] = reward + reward_decay * q_target[max_q_target];
//Compute error
float[] error = new float[actions.Length];
for (int j = 0; j < actions.Length; j++)
{
error[j] = q_target[j] - q_eval[j];
}
//Update weights using RMS-PROP
network_eval.UpdateWeights(error);
}
//Update epsilon
if (epsilon < max_epsilon)
{
epsilon += epsilon_increment;
}
else
{
epsilon = max_epsilon;
}
//Update learn step
learn_step++;
}
private float MSR(float[][] data, MFNN network)
{
int input_size = network.GetInputSize();
int output_size = network.GetOutputSize();
//Error Checking
Debug.Assert(data.Length > 0);
Debug.Assert(data[0].Length == input_size + output_size);
float msr = 0;
for (int i = 0; i < data.Length; i++)
{
float[] x_values = new float[input_size];
float[] t_values = new float[output_size];
Array.Copy(data[i], 0, x_values, 0, input_size);
Array.Copy(data[i], input_size, t_values, 0, output_size);
float[] y_values = network.Compute(x_values);
float sum = 0;
for (int j = 0; j < output_size; j++)
{
sum += (t_values[j] - y_values[j]) * (t_values[j] - y_values[j]);
}
msr += sum;
}
return(msr);
}
private void Start()
{
MFNN network = new MFNN(new int[] { 4, 7, 3 }, new ActivationType[] {
ActivationType.NONE,
ActivationType.LOGISTIC_SIGMOID,
ActivationType.LOGISTIC_SIGMOID
});
int[] shuffle = ShuffleArray(IrisData.dataset.Length);
Debug.Log("Initial Error: " + MSR(IrisData.dataset, network));
int input_size = network.GetInputSize();
int output_size = network.GetOutputSize();
int r = 0;
while (r < 100)
{
for (int i = 0; i < IrisData.dataset.Length - 20; i++)
{
float[] x_values = new float[input_size];
float[] t_values = new float[output_size];
Array.Copy(IrisData.dataset[shuffle[i]], 0, x_values, 0, input_size);
Array.Copy(IrisData.dataset[shuffle[i]], input_size, t_values, 0, output_size);
float[] y_values = network.Compute(x_values);
float[] errors = new float[output_size];
for (int j = 0; j < output_size; j++)
{
errors[j] = t_values[j] - y_values[j];
}
network.UpdateWeights(errors, 0.01f, 0.0001f, 0.5f);
}
Debug.Log("Itr. " + r + " MSR: " + MSR(IrisData.dataset, network));
r++;
}
Debug.Log("Testing");
for (int i = IrisData.dataset.Length - 21; i < IrisData.dataset.Length; i++)
{
float[] x_values = new float[input_size];
float[] t_values = new float[output_size];
Array.Copy(IrisData.dataset[shuffle[i]], 0, x_values, 0, input_size);
Array.Copy(IrisData.dataset[shuffle[i]], input_size, t_values, 0, output_size);
float[] y_values = network.Compute(x_values);
int max1 = 0;
int max2 = 0;
for (int j = 0; j < t_values.Length; j++)
{
if (t_values[max1] < t_values[j])
{
max1 = j;
}
if (y_values[max2] < y_values[j])
{
max2 = j;
}
}
if (max1 == max2)
{
Debug.Log("GOOD");
}
else
{
Debug.Log("BAD");
}
}
}
private IEnumerator TakeStep()
{
//Get current car state
float[] current_state = car_camera.GetRays();
//Get action from current state
float[] q_values = particles[working_particle].Compute(current_state);
last_q_values = q_values;
action_index = SelectAction(q_values);
//Wait for action to complete
yield return(new WaitForSeconds(0.1f));
//Get next state
float[] next_state = car_camera.GetRays();
//Get max `a` of `q_target`
float[] q_target = network_target.Compute(next_state);
int max_q_target = 0;
for (int i = 1; i < max_q_target; i++)
{
if (q_target[max_q_target] < q_target[i])
{
max_q_target = i;
}
}
//Get rward for action
float velocity = car_body.gameObject.transform.InverseTransformDirection(car_body.velocity).z;
current_reward = velocity + reward_decay * q_target[max_q_target];
particles[working_particle].SetNetworkScore(current_reward);
//Reset car if stuck after 100 steps
if (car_body.velocity.magnitude < 0.3f && current_step - reset_step > 100)
{
reset_step = current_step;
car_body.transform.position = car_spawner.transform.position;
car_body.transform.rotation = car_spawner.transform.rotation;
car_body.velocity = Vector3.zero;
car_body.angularVelocity = Vector3.zero;
}
//After 300 steps go to next particle
if (current_step - particle_step > next_particle_wait)
{
working_particle++;
//reset reward
current_reward = 0;
particle_step = current_step;
}
//Do a pso update after all particles
if (working_particle == max_particles)
{
network_target.SetWeightsData(particle_swarm.GetBestWeights());
//PSO Update Step
particle_swarm.ComputeEpoch();
particle_swarm.UpdateWeights();
working_particle = 0;
}
current_step++;
if (!abort_learning)
{
StartCoroutine(TakeStep());
}
}