diff --git a/utils/predict.py b/utils/predict.py index 8fd96dc..301a86b 100644 --- a/utils/predict.py +++ b/utils/predict.py @@ -1,47 +1,69 @@ import numpy as np import datetime -import matplotlib.pyplot as plt +import pandas as pd +from pmdarima import auto_arima - -def datetime_to_number(date: str): # 格式化日期转换为 integer +def datetime_to_number(date: str): + """Convert a date string 'YYYY-MM-DD' to a relative day number.""" date_number = datetime.datetime.strptime(date, "%Y-%m-%d") base_number = datetime.datetime.strptime("2024-1-1", "%Y-%m-%d") return (date_number - base_number).days +def predict_future_values(data, forecast_days=5): + """ + Use auto_arima from pmdarima to fit a suitable ARIMA/SARIMA model for the time series, + then predict future values for the specified number of days. -def predict_future_values(data): - # 提取并排序日期 - sorted_dates = sorted(data.keys(), key=lambda date: datetime.datetime.strptime(date, "%Y-%m-%d")) - sorted_data = {k: data[k] for k in sorted_dates} + Parameters: + data: dict, keys are date strings 'YYYY-MM-DD', values are integer counts + forecast_days: int, number of days to predict into the future - # 将日期转换为整数并提取相应的值 - xs = np.array([datetime_to_number(date) for date in sorted_data.keys()]) - ys = np.array([data[date] for date in sorted_data.keys()]) + Returns: + predictions: dict, keys are future date strings 'YYYY-MM-DD', values are predicted integers (≥0) + """ + if not data: + return {} - # 拟合线性回归模型 - fit = np.polyfit(xs, ys, 1) - fn = np.poly1d(fit) + # Sort data by date + sorted_dates = sorted(data.keys(), key=lambda d: datetime.datetime.strptime(d, "%Y-%m-%d")) + start_date = sorted_dates[0] + end_date = sorted_dates[-1] + + # Create a full date range to ensure continuity in the time series + full_range = pd.date_range(start=start_date, end=end_date, freq='D') + ts = pd.Series(0, index=full_range, dtype=float) + for d in data: + ts[pd.to_datetime(d)] = data[d] - # 获取最新日期,并生成未来三天的日期 - latest_date = sorted_dates[-1] - latest_date_obj = datetime.datetime.strptime(latest_date, "%Y-%m-%d") - future_dates = [(latest_date_obj + datetime.timedelta(days=i)).strftime("%Y-%m-%d") for i in range(1, 6)] - - # 预测未来日期的值 + # Simple smoothing: optional step to reduce noise (moving average over 3 days) + # This is a mild smoothing to handle noisy data. You can comment this out if not needed. + ts_smoothed = ts.rolling(window=3, min_periods=1).mean() + + # Fit the time series with auto_arima to find the best parameters + model = auto_arima(ts_smoothed, + start_p=1, start_q=1, + max_p=5, max_q=5, + seasonal=False, + trace=False, error_action='ignore', suppress_warnings=True, stepwise=True) + + # Predict the future values + forecast = model.predict(n_periods=forecast_days) + # Construct future dates + last_date = pd.to_datetime(end_date) + future_dates = [last_date + datetime.timedelta(days=i) for i in range(1, forecast_days+1)] + + # Convert forecast results to dict with non-negative integers predictions = {} - for date in future_dates: - date_num = datetime_to_number(date) - if int(fn(date_num))<=0: - predictions[date] = 0 - else: - predictions[date] = int(fn(date_num)) + for d, v in zip(future_dates, forecast): + predictions[d.strftime("%Y-%m-%d")] = max(int(round(v)), 0) return predictions - if __name__ == '__main__': - data = {'2024-06-15': 1, '2024-06-18': 1, '2024-06-22': 1, '2024-06-23': 1, '2024-07-01': 3, '2024-07-02': 4, '2024-07-03': 4, '2024-07-04': 14} - predictions = predict_future_values(data) - print(predictions) - # for date, value in predictions.items(): - # print(f'{date} PREDICTION: {value}') + data = { + '2024-06-15': 1, '2024-06-18': 1, '2024-06-22': 1, + '2024-06-23': 1, '2024-07-01': 3, '2024-07-02': 4, + '2024-07-03': 4, '2024-07-04': 14 + } + preds = predict_future_values(data) + print(preds)