diff --git a/Graphs/A*.py b/Graphs/A*.py deleted file mode 100644 index 2ca9476e5..000000000 --- a/Graphs/A*.py +++ /dev/null @@ -1,101 +0,0 @@ - -grid = [[0, 1, 0, 0, 0, 0], - [0, 1, 0, 0, 0, 0],#0 are free path whereas 1's are obstacles - [0, 1, 0, 0, 0, 0], - [0, 1, 0, 0, 1, 0], - [0, 0, 0, 0, 1, 0]] - -''' -heuristic = [[9, 8, 7, 6, 5, 4], - [8, 7, 6, 5, 4, 3], - [7, 6, 5, 4, 3, 2], - [6, 5, 4, 3, 2, 1], - [5, 4, 3, 2, 1, 0]]''' - -init = [0, 0] -goal = [len(grid)-1, len(grid[0])-1] #all coordinates are given in format [y,x] -cost = 1 - -#the cost map which pushes the path closer to the goal -heuristic = [[0 for row in range(len(grid[0]))] for col in range(len(grid))] -for i in range(len(grid)): - for j in range(len(grid[0])): - heuristic[i][j] = abs(i - goal[0]) + abs(j - goal[1]) - if grid[i][j] == 1: - heuristic[i][j] = 99 #added extra penalty in the heuristic map - - -#the actions we can take -delta = [[-1, 0 ], # go up - [ 0, -1], # go left - [ 1, 0 ], # go down - [ 0, 1 ]] # go right - - -#function to search the path -def search(grid,init,goal,cost,heuristic): - - closed = [[0 for col in range(len(grid[0]))] for row in range(len(grid))]# the referrence grid - closed[init[0]][init[1]] = 1 - action = [[0 for col in range(len(grid[0]))] for row in range(len(grid))]#the action grid - - x = init[0] - y = init[1] - g = 0 - f = g + heuristic[init[0]][init[0]] - cell = [[f, g, x, y]] - - found = False # flag that is set when search is complete - resign = False # flag set if we can't find expand - - while not found and not resign: - if len(cell) == 0: - resign = True - return "FAIL" - else: - cell.sort()#to choose the least costliest action so as to move closer to the goal - cell.reverse() - next = cell.pop() - x = next[2] - y = next[3] - g = next[1] - f = next[0] - - - if x == goal[0] and y == goal[1]: - found = True - else: - for i in range(len(delta)):#to try out different valid actions - x2 = x + delta[i][0] - y2 = y + delta[i][1] - if x2 >= 0 and x2 < len(grid) and y2 >=0 and y2 < len(grid[0]): - if closed[x2][y2] == 0 and grid[x2][y2] == 0: - g2 = g + cost - f2 = g2 + heuristic[x2][y2] - cell.append([f2, g2, x2, y2]) - closed[x2][y2] = 1 - action[x2][y2] = i - invpath = [] - x = goal[0] - y = goal[1] - invpath.append([x, y])#we get the reverse path from here - while x != init[0] or y != init[1]: - x2 = x - delta[action[x][y]][0] - y2 = y - delta[action[x][y]][1] - x = x2 - y = y2 - invpath.append([x, y]) - - path = [] - for i in range(len(invpath)): - path.append(invpath[len(invpath) - 1 - i]) - print "ACTION MAP" - for i in range(len(action)): - print action[i] - - return path - -a = search(grid,init,goal,cost,heuristic) -for i in range(len(a)): - print a[i] -