{"type":"doc","content":[{"type":"extension","attrs":{"layout":"default","extensionType":"com.atlassian.confluence.macro.core","extensionKey":"toc","parameters":{"macroParams":{},"macroMetadata":{"macroId":{"value":"915b9060-0fa6-492e-86aa-8886929d2c55"},"schemaVersion":{"value":"1"},"title":"Table of Contents"}},"localId":"4dc82161-ec25-4b54-8a9e-66653cfd8c11"}},{"type":"heading","attrs":{"level":1},"content":[{"text":"Overview","type":"text"}]},{"type":"paragraph","content":[{"text":"This guide is for reviewers of bootcamp submissions.","type":"text"}]},{"type":"paragraph","content":[{"text":"If you are a bootcamper, please close this page and go to the bootcamp","type":"text","marks":[{"type":"strong"}]},{"text":".","type":"text"}]},{"type":"paragraph","content":[{"text":"Members who wish to become bootcamp reviewers, please complete the bootcamp in full (with PR accepted) before continuing.","type":"text"}]},{"type":"heading","attrs":{"level":1},"content":[{"text":"PR review","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Comments","type":"text"}]},{"type":"paragraph","content":[{"text":"If the bootcamper omitted something required or has done something that is not allowed in this guide, they must fix their code.","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Normal PR review comment.","type":"text"}]}]}]},{"type":"paragraph","content":[{"text":"Unideal: The bootcamper does not need to change anything.","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Add ","type":"text"},{"text":"(You do not need to change anything here, just something to think about).","type":"text","marks":[{"type":"code"}]},{"text":" after your PR review comment.","type":"text"}]}]}]},{"type":"paragraph","content":[{"text":"If you see something particularly good, add a comment!","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Add ","type":"text"},{"text":"(You do not need to change anything here).","type":"text","marks":[{"type":"code"}]},{"text":" as well to prevent confusion.","type":"text"}]}]}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Completion","type":"text"}]},{"type":"paragraph","content":[{"text":"Once the bootcamper’s submission is accepted, add your review:","type":"text"}]},{"type":"orderedList","attrs":{"order":1},"content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Under the title on the right, click Files changed.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"On the right, click the green Review changes dropdown.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Write ","type":"text"},{"text":"LGTM.","type":"text","marks":[{"type":"code"}]},{"text":" .","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Ensure the Comment option is selected, DO NOT SELECT APPROVE","type":"text","marks":[{"type":"strong"}]},{"text":".","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Click the green Submit review.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Under the title, click Conversation.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Scroll to the bottom and close the PR.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Send this message in the bootcamper’s Discord thread: ","type":"text"},{"text":"You've completed the bootcamp! Please follow the new member onboarding procedure: https://uwarg-docs.atlassian.net/wiki/spaces/AD/pages/1697349760 . Please join Autonomy meetings which are every week on [day] at [time]!","type":"text","marks":[{"type":"code"}]}]},{"type":"orderedList","attrs":{"order":1},"content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Replace ","type":"text"},{"text":"[day]","type":"text","marks":[{"type":"code"}]},{"text":" and ","type":"text"},{"text":"[time]","type":"text","marks":[{"type":"code"}]},{"text":" with the appropriate day of the week and time respectively.","type":"text"}]}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Remove the New Bootcamper role from the new member (if you are not a lead, ping the Autonomy leads to do this).","type":"text"}]}]}]},{"type":"heading","attrs":{"level":1},"content":[{"text":"Coding style","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must follow the Python style guide: ","type":"text"},{"type":"inlineCard","attrs":{"url":"https://uwarg-docs.atlassian.net/wiki/spaces/CV/pages/2253226033"}},{"text":" . At the very least, naming and spacing convention needs to be followed.","type":"text"}]},{"type":"paragraph","content":[{"text":"Type hints are not explicitly required but are good to see!","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Floating point comparisons","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must not use ","type":"text"},{"text":"==","type":"text","marks":[{"type":"code"}]},{"text":" or ","type":"text"},{"text":"!=","type":"text","marks":[{"type":"code"}]},{"text":" operators with floating point values. An alternative is to use a tolerance: ","type":"text"},{"text":"abs(a - b) < tolerance","type":"text","marks":[{"type":"code"}]},{"text":" .","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"__eq__()","type":"text","marks":[{"type":"code"}]},{"text":" in ","type":"text"},{"text":"DroneReport","type":"text","marks":[{"type":"code"}]},{"text":" and ","type":"text"},{"text":"Location","type":"text","marks":[{"type":"code"}]},{"text":" is a trap. This is to teach that not all APIs should be used.","type":"text"}]}]}]},{"type":"paragraph","content":[{"text":"Using the operators ","type":"text"},{"text":">=","type":"text","marks":[{"type":"code"}]},{"text":" , ","type":"text"},{"text":">","type":"text","marks":[{"type":"code"}]},{"text":" , ","type":"text"},{"text":"<","type":"text","marks":[{"type":"code"}]},{"text":" , and ","type":"text"},{"text":"<=","type":"text","marks":[{"type":"code"}]},{"text":" are fine.","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"No raised exceptions","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must not raise any exceptions at runtime. Any assertions must only be for quieting the linter and must be impossible to encounter at runtime. For example:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"if not result:\n # return/continue/break\n\n# This will never be False because of the above\nassert result","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Commented out and unreachable code","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must not leave any commented out code nor unreachable code. It must be deleted.","type":"text"}]},{"type":"paragraph","content":[{"text":"This occurs because the bootcamper has a habit of information hoarding: What if the code is needed again? But since Git and GitHub are used for version control, it is discouraged.","type":"text"}]},{"type":"heading","attrs":{"level":1},"content":[{"text":"Pythonic expressions","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must use Pythonic expressions wherever possible.","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Iterating","type":"text"}]},{"type":"paragraph","content":[{"text":"Prefer:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"for thing in things: # Where `things` is iterable (e.g. list, tuple, dictionary)\n do_something(thing)","type":"text"}]},{"type":"paragraph","content":[{"text":"Instead of:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"for i in range(0, len(things)):\n do_something(things[i])","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Tuple assignment","type":"text"}]},{"type":"paragraph","content":[{"text":"Prefer:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"car_type: str, year: int = get_car_info()","type":"text"}]},{"type":"paragraph","content":[{"text":"Instead of:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"car_info: tuple[str, int] = get_car_info()\ncar_type: str = car_info[0]\nyear: int = car_info[1]","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Private members and methods","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must not access private members and/or methods outside of the scope it is declared.","type":"text"}]},{"type":"heading","attrs":{"level":1},"content":[{"text":"Bootcamp specific","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must keep code changes within the designated markers:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"# ============\n# ↓ BOOTCAMPERS MODIFY BELOW THIS COMMENT ↓\n# ============\n\n# ============\n# ↑ BOOTCAMPERS MODIFY ABOVE THIS COMMENT ↑\n# ============","type":"text"}]},{"type":"paragraph","content":[{"text":"Changing or adding code outside of the designated markers is not allowed, except for adding new helper methods within the class in task 3 and task 4.","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must not import any additional libraries.","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Task 1","type":"text"}]},{"type":"paragraph","content":[{"text":"ChatGPT will get most of the way there, but does not actually provide a working solution with the loop.","type":"text"}]},{"type":"paragraph","content":[{"text":"Relevant Ultralytics documentation: ","type":"text"},{"type":"inlineCard","attrs":{"url":"https://docs.ultralytics.com/modes/predict/"}},{"text":" ","type":"text"}]},{"type":"paragraph","content":[{"text":"Relevant verbosity documentation: ","type":"text"},{"type":"inlineCard","attrs":{"url":"https://stackoverflow.com/questions/76213454/hide-ultralytics-yolov8-model-predict-output-from-terminal"}},{"text":" ","type":"text"}]},{"type":"expand","attrs":{"title":"predictions = ..."},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"Sample solution:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"predictions = self.__model.predict(\n source=image, # Input image on which to run inference\n conf=0.7, # Minimum confidence threshold for detection\n device=self.__DEVICE, # Hardware device on which to run inference\n verbose=False, # Enable/disable printing to console\n)","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must use the ","type":"text"},{"text":"predict()","type":"text","marks":[{"type":"code"}]},{"text":" method and not the ","type":"text"},{"text":"()","type":"text","marks":[{"type":"code"}]},{"text":" operator.","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"This is not allowed: ","type":"text"},{"text":"predictions = self.__model(source=...)","type":"text","marks":[{"type":"code"}]}]}]}]},{"type":"paragraph","content":[{"text":"The arguments can be magic numbers or class constants. Global constants must not be used.","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must set all 4 arguments.","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"conf","type":"text","marks":[{"type":"code"}]},{"text":" must be within 0.4 and 0.8 (inclusive).","type":"text"}]}]}]},{"type":"paragraph","content":[{"text":"predictions","type":"text","marks":[{"type":"code"}]},{"text":" is a ","type":"text"},{"text":"list[Results]","type":"text","marks":[{"type":"code"}]},{"text":" , where ","type":"text"},{"text":"len(predictions)","type":"text","marks":[{"type":"code"}]},{"text":" is 1 (as 1 image is passed in).","type":"text"}]}]},{"type":"expand","attrs":{"title":"prediction = ..."},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"Sample solution:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"prediction = predictions[0]","type":"text"}]},{"type":"paragraph","content":[{"text":"Just get the ","type":"text"},{"text":"Results","type":"text","marks":[{"type":"code"}]},{"text":" object.","type":"text"}]}]},{"type":"expand","attrs":{"title":"image_annotated = ..."},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"Sample solution:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"image_annotated = prediction.plot(\n conf=True, # Enable/disable confidence labels on bounding boxes\n)","type":"text"}]},{"type":"paragraph","content":[{"text":"The arguments can be magic numbers or class constants. Global constants must not be used.","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must use ","type":"text"},{"text":"conf=True","type":"text","marks":[{"type":"code"}]},{"text":" .","type":"text"}]},{"type":"paragraph","content":[{"text":"image_annotated","type":"text","marks":[{"type":"code"}]},{"text":" is a ","type":"text"},{"text":"np.ndarray","type":"text","marks":[{"type":"code"}]},{"text":" of the same shape as the input image. The logged image is annotated with the bounding boxes and confidence labels.","type":"text"}]}]},{"type":"expand","attrs":{"title":"boxes_xyxy = ..."},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"Sample solution:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"boxes_xyxy = prediction.boxes.xyxy","type":"text"}]},{"type":"paragraph","content":[{"text":"Get the ","type":"text"},{"text":"Boxes","type":"text","marks":[{"type":"code"}]},{"text":" object and then the bounds in ","type":"text"},{"text":"xyxy","type":"text","marks":[{"type":"code"}]},{"text":" form.","type":"text"}]},{"type":"paragraph","content":[{"text":"boxes_xyxy","type":"text","marks":[{"type":"code"}]},{"text":" is a Pytorch tensor in the GPU memory of shape (n, 4) , where n is the number of detections from the image.","type":"text"}]}]},{"type":"expand","attrs":{"title":"boxes_cpu = ..."},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"Sample solution:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"boxes_cpu = boxes_xyxy.detach().cpu().numpy()","type":"text"}]},{"type":"paragraph","content":[{"text":"Chained methods:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"detach()","type":"text","marks":[{"type":"code"}]},{"text":" : Removes gradient information from the Pytorch tensor in the GPU memory.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"cpu()","type":"text","marks":[{"type":"code"}]},{"text":" : Moves the Pytorch tensor into CPU memory.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"numpy()","type":"text","marks":[{"type":"code"}]},{"text":" : Converts the Pytorch tensor into a numpy array.","type":"text"}]}]}]},{"type":"paragraph","content":[{"text":"boxes_cpu","type":"text","marks":[{"type":"code"}]},{"text":" is a numpy array of shape (n, 4) , where n is the number of detections from the image.","type":"text"}]}]},{"type":"expand","attrs":{"title":"Loop"},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"Sample solution:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"bounding_boxes = [] # Bounding box list to return\nfor i in range(0, boxes_cpu.shape[0]): # Loop over each detection\n result, box = bounding_box.BoundingBox.create(boxes_cpu[i]) # Convert the xyxy detection\n if not result: # Check if successful\n return [], image_annotated # If any failure, return empty list\n bounding_boxes.append(box) # Push bounding box onto end of list","type":"text"}]},{"type":"paragraph","content":[{"text":"Within the loop, bounding box creation, check, and append are mandatory.","type":"text"}]},{"type":"paragraph","content":[{"text":"Bounding box creation:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The bootcamper must not write: ","type":"text"},{"text":"box = bounding_box.BoundingBox.create(boxes_cpu[i])[1]","type":"text","marks":[{"type":"code"}]}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Not proper tuple assignment","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Ignores boolean result","type":"text"}]}]}]}]}]},{"type":"paragraph","content":[{"text":"Check:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The bootcamper must include the check, which is used to ensure bounding box creation is successful (as there is a possibility of it failing).","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The bootcamper must not use: ","type":"text"},{"text":"if box is None:","type":"text","marks":[{"type":"code"}]}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The boolean should be checked instead. This is the convention used in the subteam, as a value of ","type":"text"},{"text":"None","type":"text","marks":[{"type":"code"}]},{"text":" could be acceptable elsewhere, but we want to know the difference between ","type":"text"},{"text":"False, None","type":"text","marks":[{"type":"code"}]},{"text":" (failure, don’t use) and ","type":"text"},{"text":"True, None","type":"text","marks":[{"type":"code"}]},{"text":" (success, do use).","type":"text"}]}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"On the failure case, the bootcamper may write:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"continue","type":"text","marks":[{"type":"code"}]},{"text":" : Unideal. In statistics, an invalid portion of the data point involves removing the entirety of the data point (where the data point here is an image, as each image is independent).","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"break","type":"text","marks":[{"type":"code"}]},{"text":" : Only if setting ","type":"text"},{"text":"bounding_boxes = []","type":"text","marks":[{"type":"code"}]},{"text":" . Returning a subset of valid bounding boxes is not allowed.","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"For example: 10 detections, 7th is invalid. It makes sense to return 9 boxes, or 0 boxes, but not solely the first 6 boxes.","type":"text"}]}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"return","type":"text","marks":[{"type":"code"}]},{"text":" : Acceptable as long as it returns the correct types.","type":"text"}]}]}]}]}]},{"type":"paragraph","content":[{"text":"Append:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The bootcamper must use ","type":"text"},{"text":"append()","type":"text","marks":[{"type":"code"}]},{"text":" , not the following code: ","type":"text"},{"text":"bounding_boxes += [box]","type":"text","marks":[{"type":"code"}]},{"text":" or ","type":"text"},{"text":"bounding_boxes = bounding_boxes + [box]","type":"text","marks":[{"type":"code"}]}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"This is inefficient as the program must allocate a new list containing the box, then copy the contents of the old list and new list into another list.","type":"text"}]}]}]}]}]}]},{"type":"expand","attrs":{"title":"Return"},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"The return’s list must either be empty or contain ","type":"text"},{"text":"BoundingBox","type":"text","marks":[{"type":"code"}]},{"text":" . The list must not have the possibility to contain ","type":"text"},{"text":"None","type":"text","marks":[{"type":"code"}]},{"text":" .","type":"text"}]}]},{"type":"expand","attrs":{"title":"Full sample solution"},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"predictions = self.__model.predict(\n source=image,\n conf=0.7,\n device=self.__DEVICE,\n verbose=False,\n)\n\nprediction = predictions[0]\n\nimage_annotated = prediction.plot(conf=True)\n\nboxes_xyxy = prediction.boxes.xyxy\n\nboxes_cpu = boxes_xyxy.detach().cpu().numpy()\n\nbounding_boxes = []\nfor i in range(0, boxes_cpu.shape[0]):\n result, box = bounding_box.BoundingBox.create(boxes_cpu[i])\n if not result:\n return [], image_annotated\n bounding_boxes.append(box)\n\nreturn bounding_boxes, image_annotated","type":"text"}]}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Task 2","type":"text"}]},{"type":"paragraph","content":[{"text":"If there is a bug in the bootcamper’s task 1 that was not caught by the unit tests, it may appear in the simulator.","type":"text"}]},{"type":"paragraph","content":[{"text":"The console output may have: ","type":"text"},{"text":"WORKER ERROR: DetectLandingPad.run() exception","type":"text","marks":[{"type":"code"}]}]},{"type":"paragraph","content":[{"text":"As a start for debugging, ask the bootcamper to put print statements at the beginning of method and in the check failure case.","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Task 3","type":"text"}]},{"type":"paragraph","content":[{"text":"ChatGPT outputs code that looks somewhat correct, but fails to account for the specificities of the system.","type":"text"}]},{"type":"paragraph","content":[{"text":"There are several solutions.","type":"text"}]},{"type":"expand","attrs":{"title":"General block structure"},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"The bootcamper may have code organized like this, with the outer blocks checking the status of the drone, and the inner blocks checking the whether the drone has arrived:","type":"text"}]},{"type":"codeBlock","content":[{"text":"// Pseudocode\nif (drone is halted)\n{\n if (drone is near waypoint)\n {\n // Land the drone\n }\n else\n {\n // Move the drone to waypoint\n }\n}\n// Optional\nelse if (drone is moving)\n{\n if (drone is near waypoint)\n {\n // Halt the drone\n }\n}","type":"text"}]},{"type":"paragraph","content":[{"text":"The conditional statements may be combined:","type":"text"}]},{"type":"codeBlock","content":[{"text":"// Pseudocode\nif (drone is halted AND drone is near waypoint)\n{\n // Land the drone\n}\nelse if (drone is halted)\n{\n // Move the drone to waypoint\n}\n// Optional\nelse if (drone is moving AND drone is near waypoint)\n{\n // Halt the drone\n}","type":"text"}]},{"type":"paragraph","content":[{"text":"Unideal: The bootcamper may choose to have the drone land on the next halted state (without any additional check) after moving to the waypoint.","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"This code only works while the simulator guarantees perfect movement. If the drone halts on the way for any reason, the code will break.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"While the bootcamp specifies that the drone will always complete its movement, what if this wasn't guaranteed and it could halt on its own at any random time? (You do not need to change anything here, just something to think about).","type":"text","marks":[{"type":"code"}]}]}]}]}]},{"type":"expand","attrs":{"title":"Relative distance calculation for arrival"},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"The bootcamper may use L-2, L-1, or L-infinity norm. The bootcamper must not use any other norm.","type":"text"}]},{"type":"paragraph","content":[{"text":"L-2 norm:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The most common calculation: distance = sqrt(difference_x^2 + difference_y^2)","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Unit distance is the unit circle.","type":"text"}]}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Python code:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Regular calculation with square root: ","type":"text"},{"text":"distance = ((x2 - x1)**2 + (y2 - y1)**2)**0.5","type":"text","marks":[{"type":"code"}]}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Unideal: The square root operation is computationally expensive, so it’s better to avoid it if possible. Since this condition holds: If a < b, then a^2 < b^2 for all a, b in positive reals including 0 , it is preferred to leave the result in distance^2 (and compare with another distance^2 since squaring is less expensive).","type":"text"}]}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Using distance^2 :","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"distance_squared = (x2 - x1)**2 + (y2 - y1)**2\nif distance_squared < acceptable_distance**2:\n # Do something","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Accepted solution.","type":"text"}]}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Using ","type":"text"},{"text":"pow()","type":"text","marks":[{"type":"code"}]},{"text":" : ","type":"text"},{"text":"distance = pow(x2 - x1, 2) + pow(y2 - y1, 2)","type":"text","marks":[{"type":"code"}]}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Unideal: More difficult to read.","type":"text"}]}]}]}]}]}]}]},{"type":"paragraph","content":[{"text":"L-1 norm:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Manhattan or taxicab: distance = abs(difference_x) + abs(difference_y)","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Unit distance is a diamond/square with vertices (0,1), (1,0), (0,-1), (-1,0) . For example: (0.5,0.5) and (0.3,0.7) both have a distance of 1.","type":"text"}]}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Unideal: More restrictive than L-2.","type":"text"}]}]}]},{"type":"paragraph","content":[{"text":"L-infinity norm:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Largest magnitude of components: distance = max(abs(difference_x), abs(difference_y))","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Unit distance is a square with vertices (1,1), (1,-1), (-1, -1), (-1, 1) . For example: (0.3,1) and (0.7,1) both have a distance of 1.","type":"text"}]}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Least restrictive.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"This calculation is used by the drone simulation to determine if it has arrived at the destination, although the simulation sets the drone’s position equal to the destination so it doesn’t actually matter.","type":"text"}]}]}]}]},{"type":"expand","attrs":{"title":"Full sample solution"},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"When halted, checks whether the drone was reached the waypoint. If it has, land, otherwise move the the waypoint.","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"if report.status == drone_status.DroneStatus.HALTED:\n relative_x = self.waypoint.location_x - report.position.location_x\n relative_y = self.waypoint.location_y - report.position.location_y\n if abs(relative_x) <= self.acceptance_radius and abs(relative_y) <= self.acceptance_radius:\n command = commands.Command.create_land_command()\n else:\n command = commands.Command.create_set_relative_destination_command(relative_x, relative_y)\n\nreturn command","type":"text"}]}]},{"type":"heading","attrs":{"level":2},"content":[{"text":"Task 4","type":"text"}]},{"type":"paragraph","content":[{"text":"There are several solutions.","type":"text"}]},{"type":"expand","attrs":{"title":"General block structure"},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"The bootcamper may have code organized like this, with the outer blocks checking the status of the drone, the middle blocks checking the state machine, and the inner blocks checking if the drone has arrived:","type":"text"}]},{"type":"codeBlock","content":[{"text":"// Constructor\nself.state := waypoint leg\nself.destination := waypoint\n\n// Pseudocode\nif (drone is halted)\n{\n if (self.state is waypoint leg)\n {\n if (drone is near self.destination)\n {\n // Calculate nearest landing pad\n self.destination := nearest landing pad\n self.state := landing pad leg\n }\n else\n {\n // Move the drone to destination\n }\n }\n else if (self.state is landing pad leg)\n {\n if (drone is near self.destination)\n {\n // Land the drone\n }\n else\n {\n // Move the drone to destination\n }\n }\n}","type":"text"}]},{"type":"paragraph","content":[{"text":"There are many other possible arrangements. The bootcamper is expected to store and track a state in a new variable (if they somehow manage to get it working without doing this, I would be very surprised).","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must not use any fancy tricks to skip travelling to the waypoint before travelling to the closest landing pad.","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The specification requires the drone to arrive at the waypoint first.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Even if this requirement did not exist, the trade off of slightly better efficiency is not worth the additional complexity:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Readability: Increased complexity makes it hard to understand what the code is doing. Code is much more often read than written","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Reusability: If the requirements change (which occurs at least every year), most of the code will be discarded (or changed so much that it is basically discarded)","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Testability: Additional tests and edge cases are required to be considered.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Effort: The time and energy that would be spent on this optimization is better spent elsewhere.","type":"text"}]}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Premature optimization is the root of all evil.","type":"text"}]}]}]}]},{"type":"expand","attrs":{"title":"Closest landing pad comparison"},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"This is an easy leetcode find minimum based on property.","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must use L-2 norm to compare landing pad distances","type":"text","marks":[{"type":"strong"}]},{"text":".","type":"text"}]},{"type":"paragraph","content":[{"text":"The bootcamper must not calculate the closest distance of the first landing pad twice (e.g. on initialization followed by loop).","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"It is inefficient to calculate the same thing twice.","type":"text"}]}]}]},{"type":"paragraph","content":[{"text":"Unideal: The bootcamper may calculate the initial landing pad distance with the first landing pad before entering the loop.","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The code only works if there is guaranteed to be at least 1 detected landing pad near the waypoint. If there is 0, the code breaks.","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"While the bootcamp specifies at least 1 landing pad, what happens if there were no landing pads? (You do not need to change anything here, just something to think about).","type":"text","marks":[{"type":"code"}]}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Additionally, most likely the bootcamper will be using a non Pythonic loop (which is not allowed), a conditional block to skip the first iteration (which is messy and unideal), or slicing (which is acceptable):","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"current = things[0]\nfor thing in things[1:]:\n current = thing","type":"text"}]}]}]}]}]},{"type":"paragraph","content":[{"text":"If the bootcamper is using an initial distance without it being the distance to the first landing pad, it must have a value of infinity (e.g. ","type":"text"},{"text":"float(\"inf\")","type":"text","marks":[{"type":"code"}]},{"text":" . The bootcamper must not use a large finite value.","type":"text"}]},{"type":"paragraph","content":[{"text":"Sample solution:","type":"text"}]},{"type":"codeBlock","content":[{"text":"closest_distance_squared = float(\"inf\")\nclosest_landing_pad = None\nfor landing_pad in landing_pad_locations:\n distance_squared = get_distance_squared(drone_report.position, landing_pad)\n if distance_squared < closest_distance_squared:\n closest_distance_squared = distance_squared\n closest_landing_pad = landing_pad","type":"text"}]}]},{"type":"expand","attrs":{"title":"Full sample solution"},"marks":[{"type":"breakout","attrs":{"mode":"wide"}}],"content":[{"type":"paragraph","content":[{"text":"Constructor:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"# State:\n# 0: Waypoint leg\n# 1: Landing pad leg\nself.state = 0\n\nself.current_destination = self.waypoint","type":"text"}]},{"type":"paragraph","content":[{"text":"Waypoint leg:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"If the drone has not reached the waypoint, move to the waypoint","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Once the drone has reached the waypoint, calculate the position of the closest landing pad and set it as the destination. Transition to the next state","type":"text"}]}]}]},{"type":"paragraph","content":[{"text":"Landing pad leg:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"If the drone has not reached the landing pad, move to the landing pad","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Once the drone has reached the landing pad, land","type":"text"}]}]}]},{"type":"codeBlock","attrs":{"language":"python"},"content":[{"text":"if report.status == drone_status.DroneStatus.HALTED:\n # Waypoint leg\n if self.state == 0:\n relative_x = self.current_destination.location_x - report.position.location_x\n relative_y = self.current_destination.location_y - report.position.location_y\n\n # At the waypoint\n if abs(relative_x) <= self.acceptance_radius and abs(relative_y) <= self.acceptance_radius:\n # Calculate the nearest landing pad\n closest_distance_squared = float(\"inf\")\n closest_landing_pad = self.waypoint\n for landing_pad in landing_pad_locations:\n distance_squared = (self.waypoint.location_x - landing_pad.location_x)**2 \\\n + (self.waypoint.location_y - landing_pad.location_y)**2\n if distance_squared < closest_distance_squared:\n closest_distance_squared = distance_squared\n closest_landing_pad = landing_pad\n\n self.current_destination = closest_landing_pad\n self.state = 1\n else:\n command = commands.Command.create_set_relative_destination_command(relative_x, relative_y)\n\n # Landing pad leg\n if self.state == 1:\n relative_x = self.current_destination.location_x - report.position.location_x\n relative_y = self.current_destination.location_y - report.position.location_y\n if abs(relative_x) <= self.acceptance_radius and abs(relative_y) <= self.acceptance_radius:\n command = commands.Command.create_land_command()\n else:\n command = commands.Command.create_set_relative_destination_command(relative_x, relative_y)\n\nreturn command","type":"text"}]}]},{"type":"paragraph"}],"version":1}