.. _sec_forecasting_quickstart: Forecasting Time Series - Quick Start ===================================== Via a simple ``fit()`` call, AutoGluon can train and tune - simple forecasting models (e.g., ARIMA, ETS, Theta), - powerful deep learning models (e.g., DeepAR, Temporal Fusion Transformer), - tree-based models (e.g., XGBoost, CatBoost, LightGBM), - an ensemble that combines predictions of other models to produce multi-step ahead *probabilistic* forecasts for univariate time series data. This tutorial demonstrates how to quickly start using AutoGluon to generate hourly forecasts for the `M4 forecasting competition `__ dataset. Loading time series data as a ``TimeSeriesDataFrame`` ----------------------------------------------------- First, we import some required modules .. code:: python import pandas as pd from autogluon.timeseries import TimeSeriesDataFrame, TimeSeriesPredictor To use ``autogluon.timeseries``, we will only need the following two classes: - ``TimeSeriesDataFrame`` stores a dataset consisting of multiple time series. - ``TimeSeriesPredictor`` takes care of fitting, tuning and selecting the best forecasting models, as well as generating new forecasts. We load a subset of the M4 hourly dataset as a ``pandas.DataFrame`` .. code:: python df = pd.read_csv("https://autogluon.s3.amazonaws.com/datasets/timeseries/m4_hourly_subset/train.csv") df.head() .. raw:: html
item_id timestamp target
0 H1 1750-01-01 00:00:00 605.0
1 H1 1750-01-01 01:00:00 586.0
2 H1 1750-01-01 02:00:00 586.0
3 H1 1750-01-01 03:00:00 559.0
4 H1 1750-01-01 04:00:00 511.0
AutoGluon expects time series data in `long format `__. Each row of the data frame contains a single observation (timestep) of a single time series represented by - unique ID of the time series (``"item_id"``) as int or str - timestamp of the observation (``"timestamp"``) as a ``pandas.Timestamp`` or compatible format - numeric value of the time series (``"target"``) The raw dataset should always follow this format with at least three columns for unique ID, timestamp, and target value, but the names of these columns can be arbitrary. It is important, however, that we provide the names of the columns when constructing a ``TimeSeriesDataFrame`` that is used by AutoGluon. AutoGluon will raise an exception if the data doesn’t match the expected format. .. code:: python train_data = TimeSeriesDataFrame.from_data_frame( df, id_column="item_id", timestamp_column="timestamp" ) train_data.head() .. raw:: html
target
item_id timestamp
H1 1750-01-01 00:00:00 605.0
1750-01-01 01:00:00 586.0
1750-01-01 02:00:00 586.0
1750-01-01 03:00:00 559.0
1750-01-01 04:00:00 511.0
We refer to each individual time series stored in a ``TimeSeriesDataFrame`` as an *item*. For example, items might correspond to different products in demand forecasting, or to different stocks in financial datasets. This setting is also referred to as a *panel* of time series. Note that this is *not* the same as multivariate forecasting — AutoGluon generates forecasts for each time series individually, without modeling interactions between different items (time series). ``TimeSeriesDataFrame`` inherits from `pandas.DataFrame `__, so all attributes and methods of ``pandas.DataFrame`` are available in a ``TimeSeriesDataFrame``. It also provides other utility functions, such as loaders for different data formats (see :class:`autogluon.timeseries.TimeSeriesDataFrame` for details). Training time series models with ``TimeSeriesPredictor.fit`` ------------------------------------------------------------ To forecast future values of the time series, we need to create a ``TimeSeriesPredictor`` object. Models in ``autogluon.timeseries`` forecast time series *multiple steps* into the future. We choose the number of these steps — the *prediction length* (also known as the *forecast horizon*) — depending on our task. For example, our dataset contains time series measured at hourly *frequency*, so we set ``prediction_length = 48`` to train models that forecast up to 48 hours into the future. We instruct AutoGluon to save trained models in the folder ``./autogluon-m4-hourly``. We also specify that AutoGluon should rank models according to `symmetric mean absolute percentage error (sMAPE) `__, and that data that we want to forecast is stored in the column ``"target"`` of the ``TimeSeriesDataFrame``. .. code:: python predictor = TimeSeriesPredictor( prediction_length=48, path="autogluon-m4-hourly", target="target", eval_metric="sMAPE", ) predictor.fit( train_data, presets="medium_quality", time_limit=600, ) .. parsed-literal:: :class: output ================ TimeSeriesPredictor ================ TimeSeriesPredictor.fit() called Setting presets to: medium_quality Fitting with arguments: {'enable_ensemble': True, 'evaluation_metric': 'sMAPE', 'hyperparameter_tune_kwargs': None, 'hyperparameters': 'medium_quality', 'prediction_length': 48, 'random_seed': None, 'target': 'target', 'time_limit': 600} Provided training data set with 148060 rows, 200 items (item = single time series). Average time series length is 740.3. Training artifacts will be saved to: /home/ci/autogluon/docs/_build/eval/tutorials/timeseries/autogluon-m4-hourly ===================================================== AutoGluon will save models to autogluon-m4-hourly/ AutoGluon will gauge predictive performance using evaluation metric: 'sMAPE' This metric's sign has been flipped to adhere to being 'higher is better'. The reported score can be multiplied by -1 to get the metric value. Provided dataset contains following columns: target: 'target' tuning_data is None. Will use the last prediction_length = 48 time steps of each time series as a hold-out validation set. Starting training. Start time is 2023-02-04 01:00:39 Models that will be trained: ['Naive', 'SeasonalNaive', 'ETS', 'Theta', 'ARIMA', 'AutoETS', 'AutoGluonTabular', 'DeepAR'] Training timeseries model Naive. Training for up to 599.88s of the 599.88s of remaining time. -0.4341 = Validation score (-sMAPE) 0.00 s = Training runtime 5.98 s = Validation (prediction) runtime Training timeseries model SeasonalNaive. Training for up to 593.88s of the 593.88s of remaining time. -0.1686 = Validation score (-sMAPE) 0.00 s = Training runtime 0.41 s = Validation (prediction) runtime Training timeseries model ETS. Training for up to 593.46s of the 593.46s of remaining time. -0.2700 = Validation score (-sMAPE) 0.00 s = Training runtime 36.33 s = Validation (prediction) runtime Training timeseries model Theta. Training for up to 557.12s of the 557.12s of remaining time. -0.2236 = Validation score (-sMAPE) 0.00 s = Training runtime 16.91 s = Validation (prediction) runtime Training timeseries model ARIMA. Training for up to 540.19s of the 540.19s of remaining time. -0.5269 = Validation score (-sMAPE) 0.00 s = Training runtime 20.52 s = Validation (prediction) runtime Training timeseries model AutoETS. Training for up to 519.65s of the 519.65s of remaining time. -0.2381 = Validation score (-sMAPE) 0.00 s = Training runtime 119.62 s = Validation (prediction) runtime Training timeseries model AutoGluonTabular. Training for up to 400.02s of the 400.02s of remaining time. -0.1089 = Validation score (-sMAPE) 49.16 s = Training runtime 4.01 s = Validation (prediction) runtime Training timeseries model DeepAR. Training for up to 346.85s of the 346.85s of remaining time. -0.1405 = Validation score (-sMAPE) 110.25 s = Training runtime 2.93 s = Validation (prediction) runtime Fitting simple weighted ensemble. -0.1077 = Validation score (-sMAPE) 8.52 s = Training runtime 12.92 s = Validation (prediction) runtime Training complete. Models trained: ['Naive', 'SeasonalNaive', 'ETS', 'Theta', 'ARIMA', 'AutoETS', 'AutoGluonTabular', 'DeepAR', 'WeightedEnsemble'] Total runtime: 382.51 s Best model: WeightedEnsemble Best model score: -0.1077 .. parsed-literal:: :class: output Here we used the ``"medium_quality"`` presets and limited the training time to 10 minutes (600 seconds). The presets define which models AutoGluon will try to fit. For ``medium_quality`` presets, these are simple baselines (``Naive``, ``SeasonalNaive``), statistical models (``ARIMA``, ``ETS``, ``Theta``), tree-based models XGBoost, LightGBM and CatBoost wrapped by ``AutoGluonTabular``, a deep learning model ``DeepAR``, and a weighted ensemble combining these. Other available presets for ``TimeSeriesPredictor`` are ``"fast_training"``, ``"high_quality"`` and ``"best_quality"``. Higher quality presets will usually produce more accurate forecasts but take longer to train and may produce less computationally efficient models. Inside ``fit()``, AutoGluon will train as many models as possible within the given time limit. Trained models are then ranked based on their performance on an internal validation set. By default, this validation set is constructed by holding out the last ``prediction_length`` timesteps of each time series in ``train_data``. Generating forecasts with ``TimeSeriesPredictor.predict`` --------------------------------------------------------- We can now use the fitted ``TimeSeriesPredictor`` to forecast the future time series values. By default, AutoGluon will make forecasts using the model that had the best score on the internal validation set. The forecast always includes predictions for the next ``prediction_length`` timesteps, starting from the end of each time series in ``train_data``. .. code:: python predictions = predictor.predict(train_data) predictions.head() .. parsed-literal:: :class: output Global seed set to 123 Model not specified in predict, will default to the model with the best validation score: WeightedEnsemble .. raw:: html
mean 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
item_id timestamp
H1 1750-01-30 04:00:00 656.114372 585.443149 619.846842 637.488263 648.272016 656.499391 664.142341 673.257205 687.407885 719.433649
1750-01-30 05:00:00 586.323865 515.876737 550.381785 567.859066 578.617251 586.689677 594.257317 603.358807 617.538712 649.750630
1750-01-30 06:00:00 549.195173 477.522066 512.200689 530.092362 541.106824 549.451446 557.333342 566.699517 581.117846 613.746183
1750-01-30 07:00:00 512.129297 440.691317 475.142323 493.083844 504.056815 512.365382 520.295670 529.671247 543.847530 576.816137
1750-01-30 08:00:00 486.210995 414.201189 448.709973 466.497031 477.746095 486.078310 494.280166 504.023036 518.548270 551.628344
AutoGluon produces a *probabilistic* forecast: in addition to predicting the mean (expected value) of the time series in the future, models also provide the quantiles of the forecast distribution. The quantile forecasts give us an idea about the range of possible outcomes. For example, if the ``"0.1"`` quantile is equal to ``500.0``, it means that the model predicts a 10% chance that the target value will be below ``500.0``. We will now visualize the forecast and the actually observed values for one of the time series in the dataset. We plot the mean forecast, as well as the 10% and 90% quantiles to show the range of potential outcomes. .. code:: python import matplotlib.pyplot as plt # TimeSeriesDataFrame can also be loaded directly from a file test_data = TimeSeriesDataFrame.from_path("https://autogluon.s3.amazonaws.com/datasets/timeseries/m4_hourly_subset/test.csv") plt.figure(figsize=(20, 3)) item_id = "H1" y_past = train_data.loc[item_id]["target"] y_pred = predictions.loc[item_id] y_test = test_data.loc[item_id]["target"][-48:] plt.plot(y_past[-200:], label="Past time series values") plt.plot(y_pred["mean"], label="Mean forecast") plt.plot(y_test, label="Future time series values") plt.fill_between( y_pred.index, y_pred["0.1"], y_pred["0.9"], color="red", alpha=0.1, label=f"10%-90% confidence interval" ) plt.legend(); .. parsed-literal:: :class: output Loaded data from: https://autogluon.s3.amazonaws.com/datasets/timeseries/m4_hourly_subset/test.csv | Columns = 3 / 3 | Rows = 157660 -> 157660 .. figure:: output_forecasting-quickstart_a33e23_11_1.png Evaluating the performance of different models ---------------------------------------------- We can view the performance of each model AutoGluon has trained via the ``leaderboard()`` method. We provide the test data set to the leaderboard function to see how well our fitted models are doing on the unseen test data. The leaderboard also includes the validation scores computed on the internal validation dataset. In AutoGluon leaderboards, higher scores always correspond to better predictive performance. Therefore our sMAPE scores are multiplied by ``-1``, such that higher “negative sMAPE”s correspond to more accurate forecasts. .. code:: python # The test score is computed using the last # prediction_length=48 timesteps of each time series in test_data predictor.leaderboard(test_data, silent=True) .. parsed-literal:: :class: output Additional data provided, testing on additional data. Resulting leaderboard will be sorted according to test score (`score_test`). .. raw:: html
model score_test score_val pred_time_test pred_time_val fit_time_marginal fit_order
0 WeightedEnsemble -0.103661 -0.107725 6.891848 12.922808 8.522340 9
1 AutoGluonTabular -0.105318 -0.108919 4.383806 4.008490 49.155455 7
2 SeasonalNaive -0.119063 -0.168566 0.675475 0.412113 0.002674 2
3 DeepAR -0.155630 -0.140511 2.741418 2.930491 110.253879 8
4 Theta -0.194352 -0.223630 17.686495 16.914176 0.001509 4
5 AutoETS -0.195432 -0.238137 124.697685 119.621259 0.001485 6
6 ETS -0.217874 -0.269993 37.479012 36.326315 0.001464 3
7 Naive -0.453291 -0.434068 0.184462 5.983827 0.003098 1
8 ARIMA -0.518139 -0.526885 21.852686 20.521975 0.001479 5
Summary ------- We used ``autogluon.timeseries`` to make probabilistic multi-step forecasts on the M4 Hourly dataset. Check out :ref:`sec_forecasting_indepth` to learn about the advanced capabilities of AutoGluon for time series forecasting.