def test_methods(self):
self.node1 = NavNode(Point(x=0, y=0), 2, 4)
self.node1.calculate_f()
self.node2 = NavNode(Point(x=1, y=0), 2, 3)
self.node2.calculate_f()
self.node3 = NavNode(Point(x=2, y=0), 2, 2)
self.node3.calculate_f()
self.node4 = NavNode(Point(x=2, y=1), 2, 1)
self.node4.calculate_f()
self.node5 = NavNode(Point(x=2, y=0), 3, 2) # like node3
my_collection = NodePrioritySet()
my_collection.add(self.node2, self.node2.f)
my_collection.add(self.node1, self.node1.f)
my_collection.add(self.node3, self.node3.f)
self.assertFalse(my_collection.is_empty())
self.assertTrue(self.node1 in my_collection)
self.assertTrue(self.node2 in my_collection)
self.assertTrue(self.node3 in my_collection)
self.assertFalse(self.node4 in my_collection)
self.assertTrue(self.node5
in my_collection) # node5 has same position as node3
self.assertEquals(my_collection[self.node1], self.node1)
self.assertEquals(my_collection[self.node5], self.node3)
self.assertEquals(my_collection.pop(), self.node3)
self.assertEquals(my_collection.pop(), self.node2)
self.assertEquals(my_collection.pop(), self.node1)
self.assertTrue(my_collection.is_empty())
self.assertFalse(self.node1 in my_collection)
def test_methods(self):
self.node1 = NavNode(Point(x=0, y=0), 2, 4)
self.node1.calculate_f()
self.node2 = NavNode(Point(x=1, y=0), 2, 3)
self.node2.calculate_f()
self.node3 = NavNode(Point(x=2, y=0), 2, 2)
self.node3.calculate_f()
self.node4 = NavNode(Point(x=2, y=1), 2, 1)
self.node4.calculate_f()
self.node5 = NavNode(Point(x=2, y=0), 3, 2) # like node3
my_collection = NodePrioritySet()
my_collection.add(self.node2, self.node2.f)
my_collection.add(self.node1, self.node1.f)
my_collection.add(self.node3, self.node3.f)
self.assertFalse(my_collection.is_empty())
self.assertTrue(self.node1 in my_collection)
self.assertTrue(self.node2 in my_collection)
self.assertTrue(self.node3 in my_collection)
self.assertFalse(self.node4 in my_collection)
self.assertTrue(self.node5 in my_collection) # node5 has same position as node3
self.assertEquals(my_collection[self.node1], self.node1)
self.assertEquals(my_collection[self.node5], self.node3)
self.assertEquals(my_collection.pop(), self.node3)
self.assertEquals(my_collection.pop(), self.node2)
self.assertEquals(my_collection.pop(), self.node1)
self.assertTrue(my_collection.is_empty())
self.assertFalse(self.node1 in my_collection)
def test_first_in_first_out(self):
self.node1 = NavNode(Point(x=0, y=2), 2, 2)
self.node2 = NavNode(Point(x=1, y=1), 2, 2)
self.node3 = NavNode(Point(x=2, y=0), 2, 2)
my_collection = NodePrioritySet()
my_collection.add(self.node1, 4)
my_collection.add(self.node2, 4)
my_collection.add(self.node3, 4)
self.assertEquals(my_collection.pop(), self.node3)
self.assertEquals(my_collection.pop(), self.node2)
self.assertEquals(my_collection.pop(), self.node1)
def test_first_in_first_out(self):
self.node1 = NavNode(Point(x=0, y=2), 2, 2)
self.node2 = NavNode(Point(x=1, y=1), 2, 2)
self.node3 = NavNode(Point(x=2, y=0), 2, 2)
my_collection = NodePrioritySet()
my_collection.add(self.node1, 4)
my_collection.add(self.node2, 4)
my_collection.add(self.node3, 4)
self.assertEquals(my_collection.pop(), self.node3)
self.assertEquals(my_collection.pop(), self.node2)
self.assertEquals(my_collection.pop(), self.node1)
def run(self, start_node):
"""
Run the A* algorithm
start_node: must be an instance of a subclass of BaseNode
"""
open_list = NodePrioritySet()
closed_list = {}
start_node.calculate_h()
start_node.calculate_f()
open_list.add(start_node, start_node.f)
def attach_and_eval(parent_node, child_node):
child_node.set_g(parent_node.g + parent_node.get_arc_cost(child_node))
child_node.calculate_h()
child_node.calculate_f()
child_node.set_parent(parent_node)
def print_stats(_current_node, _closed_list, _open_list, _num_nodes_popped, _print_path):
print "number of nodes created:", len(_closed_list) + len(_open_list.dict)
print "number of nodes popped:", _num_nodes_popped
print "path length:", len(_current_node.get_ancestors())
if _print_path:
print "backtracked nodes that led to the solution:"
print current_node
for ancestor in ancestors:
print ancestor
# If the algorithm still hasn't found a solution after the max number of iterations,
# then the algorithm will stop
max_num_iterations = 50000000
current_node = None
num_nodes_popped = 0
for num_iterations in xrange(max_num_iterations):
if open_list.is_empty():
print 'Failed to find a solution'
print_stats(current_node, closed_list, open_list, num_nodes_popped, self.print_path)
return False, current_node
current_node = open_list.pop()
num_nodes_popped += 1
closed_list[current_node] = current_node
if not self.disable_gfx and num_iterations % self.draw_every == 0:
ancestors = current_node.get_ancestors()
self.draw(current_node, ancestors, closed_list, open_list) # draw current state
if current_node.is_solution():
print_stats(current_node, closed_list, open_list, num_nodes_popped, self.print_path)
return True, current_node
children = current_node.generate_children()
for child in children:
previously_generated = False
if child in open_list:
child = open_list[child] # re-use previously generated node
previously_generated = True
elif child in closed_list:
child = closed_list[child] # re-use previously generated node
previously_generated = True
if not previously_generated:
attach_and_eval(current_node, child)
open_list.add(child, child.f)
elif current_node.g + current_node.get_arc_cost(child) < child.g:
attach_and_eval(current_node, child)
print 'Failed to find a solution within the max number of iterations,', max_num_iterations
print_stats(current_node, closed_list, open_list, num_nodes_popped, self.print_path)
return False, current_node
def run(self, start_node):
"""
Run the A* algorithm
start_node: must be an instance of a subclass of BaseNode
"""
open_list = NodePrioritySet()
closed_list = {}
start_node.calculate_h()
start_node.calculate_f()
open_list.add(start_node, start_node.f)
def attach_and_eval(parent_node, child_node):
child_node.set_g(parent_node.g +
parent_node.get_arc_cost(child_node))
child_node.calculate_h()
child_node.calculate_f()
child_node.set_parent(parent_node)
def print_stats(_current_node, _closed_list, _open_list,
_num_nodes_popped, _print_path):
print "number of nodes created:", len(_closed_list) + len(
_open_list.dict)
print "number of nodes popped:", _num_nodes_popped
print "path length:", len(_current_node.get_ancestors())
if _print_path:
print "backtracked nodes that led to the solution:"
print current_node
for ancestor in ancestors:
print ancestor
# If the algorithm still hasn't found a solution after the max number of iterations,
# then the algorithm will stop
max_num_iterations = 50000000
current_node = None
num_nodes_popped = 0
for num_iterations in xrange(max_num_iterations):
if open_list.is_empty():
print 'Failed to find a solution'
print_stats(current_node, closed_list, open_list,
num_nodes_popped, self.print_path)
return False, current_node
current_node = open_list.pop()
num_nodes_popped += 1
closed_list[current_node] = current_node
if not self.disable_gfx and num_iterations % self.draw_every == 0:
ancestors = current_node.get_ancestors()
self.draw(current_node, ancestors, closed_list,
open_list) # draw current state
if current_node.is_solution():
print_stats(current_node, closed_list, open_list,
num_nodes_popped, self.print_path)
return True, current_node
children = current_node.generate_children()
for child in children:
previously_generated = False
if child in open_list:
child = open_list[
child] # re-use previously generated node
previously_generated = True
elif child in closed_list:
child = closed_list[
child] # re-use previously generated node
previously_generated = True
if not previously_generated:
attach_and_eval(current_node, child)
open_list.add(child, child.f)
elif current_node.g + current_node.get_arc_cost(
child) < child.g:
attach_and_eval(current_node, child)
print 'Failed to find a solution within the max number of iterations,', max_num_iterations
print_stats(current_node, closed_list, open_list, num_nodes_popped,
self.print_path)
return False, current_node
