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Примечание

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ultralytics.engine.tuner.Tuner

Класс, отвечающий за настройку гиперпараметров моделей YOLO .

Класс развивает гиперпараметры модели YOLO в течение заданного количества итераций. изменяя их в соответствии с пространством поиска и переобучая модель, чтобы оценить их эффективность.

Атрибуты:

Имя Тип Описание
space dict

Гиперпараметрическое пространство поиска, содержащее границы и масштабные коэффициенты для мутации.

tune_dir Path

Каталог, в котором будут сохраняться журналы эволюции и результаты.

tune_csv Path

Путь к CSV-файлу, в котором сохраняются журналы эволюции.

Методы:

Имя Описание
_mutate

dict) -> dict: Изменяет заданные гиперпараметры в пределах, указанных в self.space.

__call__

Выполняет эволюцию гиперпараметров в течение нескольких итераций.

Пример

Настрой гиперпараметры для YOLOv8n на COCO8 при imgsz=640 и epochs=30 для 300 итераций настройки.

from ultralytics import YOLO

model = YOLO('yolov8n.pt')
model.tune(data='coco8.yaml', epochs=10, iterations=300, optimizer='AdamW', plots=False, save=False, val=False)

Настройся на пользовательское пространство поиска.

from ultralytics import YOLO

model = YOLO('yolov8n.pt')
model.tune(space={key1: val1, key2: val2})  # custom search space dictionary

Исходный код в ultralytics/engine/tuner.py
class Tuner:
    """
    Class responsible for hyperparameter tuning of YOLO models.

    The class evolves YOLO model hyperparameters over a given number of iterations
    by mutating them according to the search space and retraining the model to evaluate their performance.

    Attributes:
        space (dict): Hyperparameter search space containing bounds and scaling factors for mutation.
        tune_dir (Path): Directory where evolution logs and results will be saved.
        tune_csv (Path): Path to the CSV file where evolution logs are saved.

    Methods:
        _mutate(hyp: dict) -> dict:
            Mutates the given hyperparameters within the bounds specified in `self.space`.

        __call__():
            Executes the hyperparameter evolution across multiple iterations.

    Example:
        Tune hyperparameters for YOLOv8n on COCO8 at imgsz=640 and epochs=30 for 300 tuning iterations.
        ```python
        from ultralytics import YOLO

        model = YOLO('yolov8n.pt')
        model.tune(data='coco8.yaml', epochs=10, iterations=300, optimizer='AdamW', plots=False, save=False, val=False)
        ```

        Tune with custom search space.
        ```python
        from ultralytics import YOLO

        model = YOLO('yolov8n.pt')
        model.tune(space={key1: val1, key2: val2})  # custom search space dictionary
        ```
    """

    def __init__(self, args=DEFAULT_CFG, _callbacks=None):
        """
        Initialize the Tuner with configurations.

        Args:
            args (dict, optional): Configuration for hyperparameter evolution.
        """
        self.space = args.pop("space", None) or {  # key: (min, max, gain(optional))
            # 'optimizer': tune.choice(['SGD', 'Adam', 'AdamW', 'NAdam', 'RAdam', 'RMSProp']),
            "lr0": (1e-5, 1e-1),  # initial learning rate (i.e. SGD=1E-2, Adam=1E-3)
            "lrf": (0.0001, 0.1),  # final OneCycleLR learning rate (lr0 * lrf)
            "momentum": (0.7, 0.98, 0.3),  # SGD momentum/Adam beta1
            "weight_decay": (0.0, 0.001),  # optimizer weight decay 5e-4
            "warmup_epochs": (0.0, 5.0),  # warmup epochs (fractions ok)
            "warmup_momentum": (0.0, 0.95),  # warmup initial momentum
            "box": (1.0, 20.0),  # box loss gain
            "cls": (0.2, 4.0),  # cls loss gain (scale with pixels)
            "dfl": (0.4, 6.0),  # dfl loss gain
            "hsv_h": (0.0, 0.1),  # image HSV-Hue augmentation (fraction)
            "hsv_s": (0.0, 0.9),  # image HSV-Saturation augmentation (fraction)
            "hsv_v": (0.0, 0.9),  # image HSV-Value augmentation (fraction)
            "degrees": (0.0, 45.0),  # image rotation (+/- deg)
            "translate": (0.0, 0.9),  # image translation (+/- fraction)
            "scale": (0.0, 0.95),  # image scale (+/- gain)
            "shear": (0.0, 10.0),  # image shear (+/- deg)
            "perspective": (0.0, 0.001),  # image perspective (+/- fraction), range 0-0.001
            "flipud": (0.0, 1.0),  # image flip up-down (probability)
            "fliplr": (0.0, 1.0),  # image flip left-right (probability)
            "bgr": (0.0, 1.0),  # image channel bgr (probability)
            "mosaic": (0.0, 1.0),  # image mixup (probability)
            "mixup": (0.0, 1.0),  # image mixup (probability)
            "copy_paste": (0.0, 1.0),  # segment copy-paste (probability)
        }
        self.args = get_cfg(overrides=args)
        self.tune_dir = get_save_dir(self.args, name="tune")
        self.tune_csv = self.tune_dir / "tune_results.csv"
        self.callbacks = _callbacks or callbacks.get_default_callbacks()
        self.prefix = colorstr("Tuner: ")
        callbacks.add_integration_callbacks(self)
        LOGGER.info(
            f"{self.prefix}Initialized Tuner instance with 'tune_dir={self.tune_dir}'\n"
            f"{self.prefix}💡 Learn about tuning at https://docs.ultralytics.com/guides/hyperparameter-tuning"
        )

    def _mutate(self, parent="single", n=5, mutation=0.8, sigma=0.2):
        """
        Mutates the hyperparameters based on bounds and scaling factors specified in `self.space`.

        Args:
            parent (str): Parent selection method: 'single' or 'weighted'.
            n (int): Number of parents to consider.
            mutation (float): Probability of a parameter mutation in any given iteration.
            sigma (float): Standard deviation for Gaussian random number generator.

        Returns:
            (dict): A dictionary containing mutated hyperparameters.
        """
        if self.tune_csv.exists():  # if CSV file exists: select best hyps and mutate
            # Select parent(s)
            x = np.loadtxt(self.tune_csv, ndmin=2, delimiter=",", skiprows=1)
            fitness = x[:, 0]  # first column
            n = min(n, len(x))  # number of previous results to consider
            x = x[np.argsort(-fitness)][:n]  # top n mutations
            w = x[:, 0] - x[:, 0].min() + 1e-6  # weights (sum > 0)
            if parent == "single" or len(x) == 1:
                # x = x[random.randint(0, n - 1)]  # random selection
                x = x[random.choices(range(n), weights=w)[0]]  # weighted selection
            elif parent == "weighted":
                x = (x * w.reshape(n, 1)).sum(0) / w.sum()  # weighted combination

            # Mutate
            r = np.random  # method
            r.seed(int(time.time()))
            g = np.array([v[2] if len(v) == 3 else 1.0 for k, v in self.space.items()])  # gains 0-1
            ng = len(self.space)
            v = np.ones(ng)
            while all(v == 1):  # mutate until a change occurs (prevent duplicates)
                v = (g * (r.random(ng) < mutation) * r.randn(ng) * r.random() * sigma + 1).clip(0.3, 3.0)
            hyp = {k: float(x[i + 1] * v[i]) for i, k in enumerate(self.space.keys())}
        else:
            hyp = {k: getattr(self.args, k) for k in self.space.keys()}

        # Constrain to limits
        for k, v in self.space.items():
            hyp[k] = max(hyp[k], v[0])  # lower limit
            hyp[k] = min(hyp[k], v[1])  # upper limit
            hyp[k] = round(hyp[k], 5)  # significant digits

        return hyp

    def __call__(self, model=None, iterations=10, cleanup=True):
        """
        Executes the hyperparameter evolution process when the Tuner instance is called.

        This method iterates through the number of iterations, performing the following steps in each iteration:
        1. Load the existing hyperparameters or initialize new ones.
        2. Mutate the hyperparameters using the `mutate` method.
        3. Train a YOLO model with the mutated hyperparameters.
        4. Log the fitness score and mutated hyperparameters to a CSV file.

        Args:
           model (Model): A pre-initialized YOLO model to be used for training.
           iterations (int): The number of generations to run the evolution for.
           cleanup (bool): Whether to delete iteration weights to reduce storage space used during tuning.

        Note:
           The method utilizes the `self.tune_csv` Path object to read and log hyperparameters and fitness scores.
           Ensure this path is set correctly in the Tuner instance.
        """

        t0 = time.time()
        best_save_dir, best_metrics = None, None
        (self.tune_dir / "weights").mkdir(parents=True, exist_ok=True)
        for i in range(iterations):
            # Mutate hyperparameters
            mutated_hyp = self._mutate()
            LOGGER.info(f"{self.prefix}Starting iteration {i + 1}/{iterations} with hyperparameters: {mutated_hyp}")

            metrics = {}
            train_args = {**vars(self.args), **mutated_hyp}
            save_dir = get_save_dir(get_cfg(train_args))
            weights_dir = save_dir / "weights"
            try:
                # Train YOLO model with mutated hyperparameters (run in subprocess to avoid dataloader hang)
                cmd = ["yolo", "train", *(f"{k}={v}" for k, v in train_args.items())]
                return_code = subprocess.run(cmd, check=True).returncode
                ckpt_file = weights_dir / ("best.pt" if (weights_dir / "best.pt").exists() else "last.pt")
                metrics = torch.load(ckpt_file)["train_metrics"]
                assert return_code == 0, "training failed"

            except Exception as e:
                LOGGER.warning(f"WARNING ❌️ training failure for hyperparameter tuning iteration {i + 1}\n{e}")

            # Save results and mutated_hyp to CSV
            fitness = metrics.get("fitness", 0.0)
            log_row = [round(fitness, 5)] + [mutated_hyp[k] for k in self.space.keys()]
            headers = "" if self.tune_csv.exists() else (",".join(["fitness"] + list(self.space.keys())) + "\n")
            with open(self.tune_csv, "a") as f:
                f.write(headers + ",".join(map(str, log_row)) + "\n")

            # Get best results
            x = np.loadtxt(self.tune_csv, ndmin=2, delimiter=",", skiprows=1)
            fitness = x[:, 0]  # first column
            best_idx = fitness.argmax()
            best_is_current = best_idx == i
            if best_is_current:
                best_save_dir = save_dir
                best_metrics = {k: round(v, 5) for k, v in metrics.items()}
                for ckpt in weights_dir.glob("*.pt"):
                    shutil.copy2(ckpt, self.tune_dir / "weights")
            elif cleanup:
                shutil.rmtree(weights_dir, ignore_errors=True)  # remove iteration weights/ dir to reduce storage space

            # Plot tune results
            plot_tune_results(self.tune_csv)

            # Save and print tune results
            header = (
                f'{self.prefix}{i + 1}/{iterations} iterations complete ✅ ({time.time() - t0:.2f}s)\n'
                f'{self.prefix}Results saved to {colorstr("bold", self.tune_dir)}\n'
                f'{self.prefix}Best fitness={fitness[best_idx]} observed at iteration {best_idx + 1}\n'
                f'{self.prefix}Best fitness metrics are {best_metrics}\n'
                f'{self.prefix}Best fitness model is {best_save_dir}\n'
                f'{self.prefix}Best fitness hyperparameters are printed below.\n'
            )
            LOGGER.info("\n" + header)
            data = {k: float(x[best_idx, i + 1]) for i, k in enumerate(self.space.keys())}
            yaml_save(
                self.tune_dir / "best_hyperparameters.yaml",
                data=data,
                header=remove_colorstr(header.replace(self.prefix, "# ")) + "\n",
            )
            yaml_print(self.tune_dir / "best_hyperparameters.yaml")

__call__(model=None, iterations=10, cleanup=True)

Выполняет процесс эволюции гиперпараметров при вызове экземпляра Tuner.

Этот метод перебирает количество итераций, выполняя на каждой из них следующие действия: 1. Загрузи существующие гиперпараметры или инициализируй новые. 2. Мутируй гиперпараметры с помощью функции mutate метод. 3. Обучи модель YOLO с измененными гиперпараметрами. 4. Занеси результаты фитнеса и мутировавшие гиперпараметры в CSV-файл.

Параметры:

Имя Тип Описание По умолчанию
model Model

Предварительно инициализированная модель YOLO , которая будет использоваться для обучения.

None
iterations int

Количество поколений, для которых нужно запустить эволюцию.

10
cleanup bool

Нужно ли удалять веса итераций, чтобы уменьшить объем памяти, используемый при настройке.

True
Примечание

Этот метод использует self.tune_csv Объект пути для чтения и записи в журнал гиперпараметров и фитнес-очков. Убедись, что этот путь правильно задан в экземпляре Tuner.

Исходный код в ultralytics/engine/tuner.py
def __call__(self, model=None, iterations=10, cleanup=True):
    """
    Executes the hyperparameter evolution process when the Tuner instance is called.

    This method iterates through the number of iterations, performing the following steps in each iteration:
    1. Load the existing hyperparameters or initialize new ones.
    2. Mutate the hyperparameters using the `mutate` method.
    3. Train a YOLO model with the mutated hyperparameters.
    4. Log the fitness score and mutated hyperparameters to a CSV file.

    Args:
       model (Model): A pre-initialized YOLO model to be used for training.
       iterations (int): The number of generations to run the evolution for.
       cleanup (bool): Whether to delete iteration weights to reduce storage space used during tuning.

    Note:
       The method utilizes the `self.tune_csv` Path object to read and log hyperparameters and fitness scores.
       Ensure this path is set correctly in the Tuner instance.
    """

    t0 = time.time()
    best_save_dir, best_metrics = None, None
    (self.tune_dir / "weights").mkdir(parents=True, exist_ok=True)
    for i in range(iterations):
        # Mutate hyperparameters
        mutated_hyp = self._mutate()
        LOGGER.info(f"{self.prefix}Starting iteration {i + 1}/{iterations} with hyperparameters: {mutated_hyp}")

        metrics = {}
        train_args = {**vars(self.args), **mutated_hyp}
        save_dir = get_save_dir(get_cfg(train_args))
        weights_dir = save_dir / "weights"
        try:
            # Train YOLO model with mutated hyperparameters (run in subprocess to avoid dataloader hang)
            cmd = ["yolo", "train", *(f"{k}={v}" for k, v in train_args.items())]
            return_code = subprocess.run(cmd, check=True).returncode
            ckpt_file = weights_dir / ("best.pt" if (weights_dir / "best.pt").exists() else "last.pt")
            metrics = torch.load(ckpt_file)["train_metrics"]
            assert return_code == 0, "training failed"

        except Exception as e:
            LOGGER.warning(f"WARNING ❌️ training failure for hyperparameter tuning iteration {i + 1}\n{e}")

        # Save results and mutated_hyp to CSV
        fitness = metrics.get("fitness", 0.0)
        log_row = [round(fitness, 5)] + [mutated_hyp[k] for k in self.space.keys()]
        headers = "" if self.tune_csv.exists() else (",".join(["fitness"] + list(self.space.keys())) + "\n")
        with open(self.tune_csv, "a") as f:
            f.write(headers + ",".join(map(str, log_row)) + "\n")

        # Get best results
        x = np.loadtxt(self.tune_csv, ndmin=2, delimiter=",", skiprows=1)
        fitness = x[:, 0]  # first column
        best_idx = fitness.argmax()
        best_is_current = best_idx == i
        if best_is_current:
            best_save_dir = save_dir
            best_metrics = {k: round(v, 5) for k, v in metrics.items()}
            for ckpt in weights_dir.glob("*.pt"):
                shutil.copy2(ckpt, self.tune_dir / "weights")
        elif cleanup:
            shutil.rmtree(weights_dir, ignore_errors=True)  # remove iteration weights/ dir to reduce storage space

        # Plot tune results
        plot_tune_results(self.tune_csv)

        # Save and print tune results
        header = (
            f'{self.prefix}{i + 1}/{iterations} iterations complete ✅ ({time.time() - t0:.2f}s)\n'
            f'{self.prefix}Results saved to {colorstr("bold", self.tune_dir)}\n'
            f'{self.prefix}Best fitness={fitness[best_idx]} observed at iteration {best_idx + 1}\n'
            f'{self.prefix}Best fitness metrics are {best_metrics}\n'
            f'{self.prefix}Best fitness model is {best_save_dir}\n'
            f'{self.prefix}Best fitness hyperparameters are printed below.\n'
        )
        LOGGER.info("\n" + header)
        data = {k: float(x[best_idx, i + 1]) for i, k in enumerate(self.space.keys())}
        yaml_save(
            self.tune_dir / "best_hyperparameters.yaml",
            data=data,
            header=remove_colorstr(header.replace(self.prefix, "# ")) + "\n",
        )
        yaml_print(self.tune_dir / "best_hyperparameters.yaml")

__init__(args=DEFAULT_CFG, _callbacks=None)

Инициализируй тюнер с помощью конфигураций.

Параметры:

Имя Тип Описание По умолчанию
args dict

Конфигурация для эволюции гиперпараметров.

DEFAULT_CFG
Исходный код в ultralytics/engine/tuner.py
def __init__(self, args=DEFAULT_CFG, _callbacks=None):
    """
    Initialize the Tuner with configurations.

    Args:
        args (dict, optional): Configuration for hyperparameter evolution.
    """
    self.space = args.pop("space", None) or {  # key: (min, max, gain(optional))
        # 'optimizer': tune.choice(['SGD', 'Adam', 'AdamW', 'NAdam', 'RAdam', 'RMSProp']),
        "lr0": (1e-5, 1e-1),  # initial learning rate (i.e. SGD=1E-2, Adam=1E-3)
        "lrf": (0.0001, 0.1),  # final OneCycleLR learning rate (lr0 * lrf)
        "momentum": (0.7, 0.98, 0.3),  # SGD momentum/Adam beta1
        "weight_decay": (0.0, 0.001),  # optimizer weight decay 5e-4
        "warmup_epochs": (0.0, 5.0),  # warmup epochs (fractions ok)
        "warmup_momentum": (0.0, 0.95),  # warmup initial momentum
        "box": (1.0, 20.0),  # box loss gain
        "cls": (0.2, 4.0),  # cls loss gain (scale with pixels)
        "dfl": (0.4, 6.0),  # dfl loss gain
        "hsv_h": (0.0, 0.1),  # image HSV-Hue augmentation (fraction)
        "hsv_s": (0.0, 0.9),  # image HSV-Saturation augmentation (fraction)
        "hsv_v": (0.0, 0.9),  # image HSV-Value augmentation (fraction)
        "degrees": (0.0, 45.0),  # image rotation (+/- deg)
        "translate": (0.0, 0.9),  # image translation (+/- fraction)
        "scale": (0.0, 0.95),  # image scale (+/- gain)
        "shear": (0.0, 10.0),  # image shear (+/- deg)
        "perspective": (0.0, 0.001),  # image perspective (+/- fraction), range 0-0.001
        "flipud": (0.0, 1.0),  # image flip up-down (probability)
        "fliplr": (0.0, 1.0),  # image flip left-right (probability)
        "bgr": (0.0, 1.0),  # image channel bgr (probability)
        "mosaic": (0.0, 1.0),  # image mixup (probability)
        "mixup": (0.0, 1.0),  # image mixup (probability)
        "copy_paste": (0.0, 1.0),  # segment copy-paste (probability)
    }
    self.args = get_cfg(overrides=args)
    self.tune_dir = get_save_dir(self.args, name="tune")
    self.tune_csv = self.tune_dir / "tune_results.csv"
    self.callbacks = _callbacks or callbacks.get_default_callbacks()
    self.prefix = colorstr("Tuner: ")
    callbacks.add_integration_callbacks(self)
    LOGGER.info(
        f"{self.prefix}Initialized Tuner instance with 'tune_dir={self.tune_dir}'\n"
        f"{self.prefix}💡 Learn about tuning at https://docs.ultralytics.com/guides/hyperparameter-tuning"
    )





Created 2023-11-12, Updated 2024-06-02
Authors: glenn-jocher (5), Burhan-Q (1)