Prepare multivariate series
Assemble a chronological table with one column per series, align timestamps, impute or flag missing values, and test for stationarity and seasonality.
Fit vector autoregression models. Assess multivariate forecasts.
Vector autoregression (VAR) models predict multiple interdependent time series by regressing each series on lagged values of all series in the system. VAR is useful when series influence each other (for example, sales across regions or sensor vectors). Key practical issues are ensuring stationarity, selecting lag order, handling missing timestamps, and evaluating with walk-forward validation.
Learning concept · Not a validated service
Vector autoregression (VAR) models predict multiple interdependent time series by regressing each series on lagged values of all series in the system. VAR is useful when series influence each other (for example, sales across regions or sensor vectors). Key practical issues are ensuring stationarity, selecting lag order, handling missing timestamps, and evaluating with walk-forward validation.
A proposed extension: a retail demand-forecasting system that jointly predicts sales for multiple SKUs, enabling coordinated inventory decisions. In practice a human planner should review model outputs before operational stock changes.
Assemble a chronological table with one column per series, align timestamps, impute or flag missing values, and test for stationarity and seasonality.
Fit a VAR model (e.g. statsmodels.tsa.api.VAR) with lag-order selection on the training folds; compare against simple univariate baselines.
Use rolling-origin (walk-forward) validation, report MAE/RMSE per series and prediction-interval coverage, and inspect cross-series error correlations.
Bundle forecasts into an API, schedule retraining, and add drift and data-quality alerts that escalate to a human reviewer.
The supplied starter creates a single synthetic univariate time series with trend, seasonality and noise, engineers lag and rolling features, then trains a RandomForestRegressor and prints MAE and a small forecast table. It does not implement a vector autoregression model or operate on multiple series.
feature_cols = ["lag_1", "lag_7", "lag_14", "rolling_7"]
train = series.iloc[:-30]
test = series.iloc[-30:]
model = RandomForestRegressor(n_estimators=300, random_state=42)
model.fit(train[feature_cols], train["value"])
forecast = model.predict(test[feature_cols])
print(PROJECT_NAME)
print("MAE:", round(mean_absolute_error(test["value"], forecast), 3))
print(pd.DataFrame({"date": test["date"], "actual": test["value"], "forecast": forecast}).head())The code only models one synthetic series with a RandomForest on lag features; it does not fit a VAR model, uses no multivariate (vector) time series, provides no lag-order selection or prediction intervals, and uses a single train/test split instead of walk-forward validation.
Proposed extension: replace the synthetic data with two or more real series (for example sales per region), fit a statsmodels VAR with lag selection, and evaluate with walk-forward validation and interval forecasts.
This is a potential application pathway, not a delivered product. The supplied starter does not implement this service or validate it with real users.
Networkers Home runs this topic inside its AI Engineer Course, with placement support and hands-on labs.