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removed unnecessary redundancy from optimizers

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This commit is contained in:
Pavel Lutskov
2018-12-17 21:49:14 +01:00
parent f390d67b1b
commit e214a3cc7d
1 changed files with 52 additions and 54 deletions
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104
main.py
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@@ -8,14 +8,21 @@ from time import time
import numpy as np
import matplotlib as mpl
mpl.use('TkAgg')
mpl.use('TkAgg') # fixes my macOS bug
import matplotlib.pyplot as plt
P = 0.1
ALPHA = 0.90
EPSILON = 1e-8 # Convergence criterium
EPSILON = 1e-12 # Convergence criterium
A2 = np.array([ # Action index to action mapping
[-1, 0], # Up
[ 1, 0], # Down
[ 0, -1], # Left
[ 0, 1], # Right
[ 0, 0], # Idle
])
# Global state
MAZE = None # Map of the environment
@@ -25,15 +32,7 @@ U_OF_X = None # The allowed action space matrix representation
PW_OF_X_U = None # The probability distribution of disturbance
G1_X = None # The cost function vector representation (depends only on state)
G2_X = None # The second cost function vector representation
F_X_U_W = None # The state function
A2 = np.array([
[-1, 0],
[1, 0],
[0, -1],
[0, 1],
[0, 0]
])
F_X_U_W = None # The System Equation
def h_matrix(j, g):
@@ -50,29 +49,30 @@ def _valid_target(target):
)
def init_global(maze_file):
def init_global(maze_filename):
global MAZE, SN, S_TO_IJ
global U_OF_X, PW_OF_X_U, F_X_U_W, G1_X, G2_X
# Basic maze structure initialization
MAZE = np.genfromtxt(
maze_file,
maze_filename,
dtype=str,
)
state_mask = (MAZE != '1')
S_TO_IJ = np.indices(MAZE.shape).transpose(1, 2, 0)[state_mask]
SN = len(S_TO_IJ)
ij_to_s = np.zeros(MAZE.shape, dtype=np.int32)
ij_to_s[state_mask] = np.arange(SN)
# One step cost functions initialization
maze_cost = np.zeros(MAZE.shape)
maze_cost = np.zeros(MAZE.shape, dtype=np.float64)
maze_cost[MAZE == '1'] = np.nan
maze_cost[(MAZE == '0') | (MAZE == 'S')] = 0
maze_cost[MAZE == 'T'] = 50
maze_cost[MAZE == 'G'] = -1
G1_X = maze_cost.copy()[state_mask]
maze_cost[maze_cost < 1] += 1 # assert np.nan < whatever == True
maze_cost[maze_cost < 1] += 1 # assert np.nan < whatever == False
G2_X = maze_cost.copy()[state_mask]
# Actual environment modelling
@@ -84,28 +84,28 @@ def init_global(maze_file):
for iu, u in enumerate(A2):
if _valid_target(x + u):
U_OF_X[ix, iu] = True
if iu in (0, 1):
possible_iw = [2, 3]
elif iu in (2, 3):
possible_iw = [0, 1]
if iu in (0, 1): # (Up, Down)
possible_iw = [2, 3] # [Left, Right]
elif iu in (2, 3): # (Left, Right)
possible_iw = [0, 1] # [Up, Down]
for iw in possible_iw:
if _valid_target(x + u + A2[iw]):
PW_OF_X_U[ix, iu, iw] = P
F_X_U_W[ix, iu, iw] = ij_to_s[tuple(x + u + A2[iw])]
# IDLE w is always possible
# Idle w is always possible
PW_OF_X_U[ix, iu, -1] = 1 - PW_OF_X_U[ix, iu].sum()
F_X_U_W[ix, iu, -1] = ij_to_s[tuple(x + u)]
def plot_j_policy_on_maze(j, policy):
heatmap = np.full(MAZE.shape, np.nan)
heatmap[S_TO_IJ[:,0], S_TO_IJ[:,1]] = j
heatmap[S_TO_IJ[:, 0], S_TO_IJ[:, 1]] = j
cmap = mpl.cm.get_cmap('coolwarm')
cmap.set_bad(color='black')
plt.imshow(heatmap, cmap=cmap)
plt.colorbar()
plt.quiver(S_TO_IJ[:,1], S_TO_IJ[:,0],
A2[policy, 1], -A2[policy, 0])
# quiver has some weird behavior, the arrow y component must be flipped
plt.quiver(S_TO_IJ[:, 1], S_TO_IJ[:, 0], A2[policy, 1], -A2[policy, 0])
plt.gca().get_xaxis().set_visible(False)
plt.gca().get_yaxis().set_visible(False)
@@ -113,7 +113,7 @@ def plot_j_policy_on_maze(j, policy):
def plot_cost_history(hist):
error = np.sqrt(np.square(hist[:-1] - hist[-1]).mean(axis=1))
plt.xlabel('Number of iterations')
plt.ylabel('Cost function error')
plt.ylabel('Cost function RMSE')
plt.plot(error)
@@ -127,7 +127,8 @@ def _evaluate_policy(policy, g):
targs = F_X_U_W[np.arange(SN), policy] # all f(x, u(x), w(x, u(x)))
G = (pw_pi * g[targs]).sum(axis=1) # Expected one-step cost vector
M = np.zeros((SN, SN)) # Markov matrix for given deterministic policy
# Markov matrix for given deterministic policy
M = np.zeros((SN, SN), dtype=np.float64)
x_from = [x_ff for x_f, nz in
zip(np.arange(SN), np.count_nonzero(pw_pi, axis=1))
for x_ff in [x_f] * nz]
@@ -135,35 +136,31 @@ def _evaluate_policy(policy, g):
return np.linalg.solve(np.eye(SN) - ALPHA*M, G)
def value_iteration(g, return_history=False):
j = np.zeros(SN)
history = [j]
while True:
# print(j)
policy, j_new = _policy_improvement(j, g)
j_old = j
j = j_new
if return_history:
history.append(j)
if np.abs(j - j_old).max() < EPSILON:
break
if not return_history:
return j, policy
else:
return np.array(history)
def value_iteration(j, g):
return _policy_improvement(j, g)
def policy_iteration(g, return_history=False):
j = None
policy = np.full(SN, len(A2) - 1) # starting policy is IDLE
def policy_iteration(j, g):
policy, _ = _policy_improvement(j, g)
j = _evaluate_policy(policy, g)
return policy, j
def _terminate(j, j_old):
# TODO: DIS
return np.abs(j - j_old).max() < EPSILON
def dynamic_programming(optimizer_step, g, return_history=False):
j = np.zeros(SN, dtype=np.float64)
history = []
while True:
j_old = j
j = _evaluate_policy(policy, g)
policy, j = optimizer_step(j, g)
if return_history:
history.append(j)
if j_old is not None and np.abs(j - j_old).max() < EPSILON:
if _terminate(j, j_old):
break
policy, _ = _policy_improvement(j, g)
if not return_history:
return j, policy
else:
@@ -190,10 +187,10 @@ if __name__ == '__main__':
plt.suptitle('DISCOUNT = ' + str(a))
i = 1
for opt in ['Value Iteration', 'Policy Iteration']:
for g in ['g1', 'g2']:
name = ' / '.join([opt, g])
for cost in ['g1', 'g2']:
name = ' / '.join([opt, cost])
ALPHA = a
j, policy = optimizers[opt](costs[g])
j, policy = dynamic_programming(optimizers[opt], costs[cost])
print(name, j)
plt.subplot(2, 2, i)
plt.gca().set_title(name)
@@ -205,11 +202,12 @@ if __name__ == '__main__':
plt.figure()
plt.suptitle(opt)
i = 1
for g in ['g1', 'g2']:
for cost in ['g1', 'g2']:
for a in [0.9, 0.8, 0.7]:
name = 'Cost: {}, discount: {}'.format(g, a)
name = 'Cost: {}, discount: {}'.format(cost, a)
ALPHA = a
history = optimizers[opt](costs[g], return_history=True)
history = dynamic_programming(optimizers[opt], costs[cost],
return_history=True)
plt.subplot(2, 3, i)
plt.gca().set_title(name)
plot_cost_history(history)