robot_class.py

from math import *
import random

class robot:

    # --------
    # init: 
    #   creates a robot with the specified parameters and initializes 
    #   the location (self.x, self.y) to the center of the world
    #
    def __init__(self, world_size = 100.0, measurement_range = 30.0,
                 motion_noise = 1.0, measurement_noise = 1.0):
        self.measurement_noise = 0.0
        self.world_size = world_size
        self.measurement_range = measurement_range
        self.x = world_size / 2.0
        self.y = world_size / 2.0
        self.motion_noise = motion_noise
        self.measurement_noise = measurement_noise
        self.landmarks = []
        self.num_landmarks = 0


    # returns a positive, random float
    def rand(self):
        return random.random() * 2.0 - 1.0


    # --------
    # move: attempts to move robot by dx, dy. If outside world
    #       boundary, then the move does nothing and instead returns failure
    #
    def move(self, dx, dy):

        x = self.x + dx + self.rand() * self.motion_noise
        y = self.y + dy + self.rand() * self.motion_noise

        if x < 0.0 or x > self.world_size or y < 0.0 or y > self.world_size:
            return False
        else:
            self.x = x
            self.y = y
            return True
    

    # --------
    # sense: returns x- and y- distances to landmarks within visibility range
    #        because not all landmarks may be in this range, the list of measurements
    #        is of variable length. Set measurement_range to -1 if you want all
    #        landmarks to be visible at all times
    #
    
    ## TODO: complete the sense function
    def sense(self):
        
        measurements = []
        
        for idx in range(len(self.landmarks)):
            dx= self.landmarks[idx][0]- self.x
            dy= self.landmarks[idx][0]- self.y
            dx= dx + self.rand() * self.measurement_noise
            dy= dy + self.rand() * self.measurement_noise
            
            if (abs(dx) > self.world_size) or (abs(dy) > self.world_size):
#                 print("stepping out of internal range")
                continue
            measurements.append([idx, dx, dy])
        return measurements


    def make_landmarks(self, num_landmarks):
        self.landmarks = []
        for i in range(num_landmarks):
            self.landmarks.append([round(random.random() * self.world_size),
                                   round(random.random() * self.world_size)])
        self.num_landmarks = num_landmarks
    
    
    # called when print(robot) is called; prints the robot's location
    def __repr__(self):
        return 'Robot: [x=%.5f y=%.5f]'  % (self.x, self.y)

####### END robot class #######