โš ๏ธ This is an AI-generated test article for theme demonstration/testing only. All content is synthetic.

Components of a time series

Trend, seasonality, and noise make up most observed series. Decomposing them is the first modelling step.

A simple baseline

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import pandas as pd
from statsmodels.tsa.holtwinters import ExponentialSmoothing

series = pd.read_csv("sales.csv", index_col="date", parse_dates=True)
model = ExponentialSmoothing(series, trend="add", seasonal="add", seasonal_periods=12)
fit = model.fit()
forecast = fit.forecast(12)
print(forecast)

Stationarity

Many models assume a stationary series; differencing is the usual fix.

Validation

Always forecast on a held-out window, never the whole history.

Keep it simple

A naive baseline often beats a complex model for short horizons.