si23traktor/agent/methods/a_star.py
2023-06-19 15:56:25 +02:00

136 lines
5.2 KiB
Python

class Node:
def __init__(self, state, parent='', action='', distance=0):
self.state = state
self.parent = parent
self.action = action
self.distance = distance
class Search:
def __init__(self, cell_size, cell_number):
self.cell_size = cell_size
self.cell_number = cell_number
def succ(self, state):
x = state[0]
y = state[1]
angle = state[2]
match(angle):
case 'UP':
possible = [['left', x, y, 'LEFT'], ['right', x, y, 'RIGHT']]
if y != 0: possible.append(['move', x, y - 1, 'UP'])
return possible
case 'RIGHT':
possible = [['left', x, y, 'UP'], ['right', x, y, 'DOWN']]
if x != (self.cell_number-1): possible.append(['move', x + 1, y, 'RIGHT'])
return possible
case 'DOWN':
possible = [['left', x, y, 'RIGHT'], ['right', x, y, 'LEFT']]
if y != (self.cell_number-1): possible.append(['move', x, y + 1, 'DOWN'])
return possible
case 'LEFT':
possible = [['left', x, y, 'DOWN'], ['right', x, y, 'UP']]
if x != 0: possible.append(['move', x - 1, y, 'LEFT'])
return possible
def cost(self, node, stones, goal, flowers):
# cost = node.distance
cost = 0
# cost += 10 if stones[node.state[0], node.state[1]] == 1 else 1
cost += 1000 if (node.state[0], node.state[1]) in stones else 1
cost += 10 if ((node.state[0]), (node.state[1])) in flowers else 1
if node.parent:
node = node.parent
cost += node.distance # should return only elem.action in prod
return cost
def heuristic(self, node, goal):
return abs(node.state[0] - goal[0]) + abs(node.state[1] - goal[1])
#bandaid to know about stones
def astarsearch(self, istate, goaltest, stone_list, plant_list):
#to be expanded
def cost_old(x, y):
if (x, y) in stones:
return 10
else:
return 1
x = istate[0]
y = istate[1]
angle = istate[2]
stones = []
flowers = []
for obj in stone_list:
stones.append((obj.xy[0]*50, obj.xy[1]*50))
for obj in plant_list:
if obj.name == 'flower':
flowers.append((obj.xy[0]*50, obj.xy[1]*50))
# stones = [(x*50, y*50) for (x, y) in stone_list]
# flowers = [(x*50, y*50) for (x, y) in plant_list]
print(stones)
# fringe = [(Node([x, y, angle]), cost_old(x, y))] # queue (moves/states to check)
fringe = [(Node([x, y, angle]))] # queue (moves/states to check)
fringe[0].distance = self.cost(fringe[0], stones, goaltest, flowers)
fringe.append((Node([x, y, angle]), self.cost(fringe[0], stones, goaltest, flowers)))
fringe.pop(0)
explored = []
while True:
if len(fringe) == 0:
return False
fringe.sort(key=lambda x: x[1])
elem = fringe.pop(0)[0]
# if goal_test(elem.state):
# return
# print(elem.state[0], elem.state[1], elem.state[2])
if elem.state[0] == goaltest[0] and elem.state[1] == goaltest[1]: # checks if we reached the given point
steps = []
while elem.parent:
steps.append([elem.action, elem.state[0], elem.state[1]]) # should return only elem.action in prod
elem = elem.parent
steps.reverse()
print(steps) # only for dev
return steps
explored.append(elem.state)
for (action, state_x, state_y, state_angle) in self.succ(elem.state):
x = Node([state_x, state_y, state_angle], elem, action)
x.parent = elem
priority = self.cost(elem, stones, goaltest, flowers) + self.heuristic(elem, goaltest)
elem.distance = priority
# priority = cost_old(x, y) + self.heuristic(elem, goaltest)
fringe_states = [node.state for (node, p) in fringe]
if x.state not in fringe_states and x.state not in explored:
fringe.append((x, priority))
elif x.state in fringe_states:
for i in range(len(fringe)):
if fringe[i][0].state == x.state:
if fringe[i][1] > priority:
fringe[i] = (x, priority)
def closest_point(self, x, y, name, plant_list):
self.max_distance = self.cell_number*self.cell_number
for obj in plant_list:
if obj.name == name:
if obj.state == 0:
self.distance = (abs(obj.xy[0] - x) + abs(obj.xy[1] - y))
if self.distance <= self.max_distance:
self.max_distance = self.distance
x_close = obj.xy[0]
y_close = obj.xy[1]
#print("distance: ",self.distance, obj.xy[0], "+", obj.xy[1], "-" ,x, "+",y)
return (x_close, y_close)