Azure ML / AutoML: problem with univariate time series forecasting

Question

I'm having troubles generating univariate time series forecasts with Azure Automated Machine Learning (I know...).

What I'm doing

So I have about 5 years worth of monthly observations in a dataframe that looks like this:

date	target_value
2015-02-01	123
2015-03-01	456
2015-04-01	789
...	...

I want to forecast target_value based on past values of target_value, i.e. univariate forecasting like ARIMA for instance.
So I am setting up the AutoML forecast like this:

# that's the dataframe as shown above
train_data = Dataset.Tabular.from_delimited_files(path=datastore.path(my_remote_filename))

# ...other code...

forecasting_parameters = ForecastingParameters(
    time_column_name='date',
    forecast_horizon=2,
    target_lags='auto',
    freq='MS'
)

automl_config = AutoMLConfig(task='forecasting',
                             debug_log='automl_forecasting_function.log',
                             primary_metric='normalized_root_mean_squared_error',
                             enable_dnn=True,
                             experiment_timeout_hours=8.0,
                             enable_early_stopping=True,
                             training_data=train_data,
                             compute_target='my-cluster',
                             n_cross_validations=3,
                             verbosity=logging.INFO,
                             max_concurrent_iterations=4,
                             max_cores_per_iteration=-1,
                             label_column_name='target_value',
                             forecasting_parameters=forecasting_parameters)

What the problem is

But AutoML does not seem to generate the forecast for target_value based on past values of target_value. It seems to use the date column as the independent variable! The feature importance chart also shows date as the input feature:

As a side note: running multivariate forecasts works fine.
When I use a dataset like this, feature_1 and feature_2 are used (i.e. as the X) to forecast target_value (i.e. the y)

date	feature_1	feature_2	target_value
2015-02-01	10	7	123
2015-03-01	30	2	456
2015-04-01	20	5	789
...	...	...	...

My questions therefore
How do I need to set up a univariate AutoML forecast to forecast target_value based on past observations target_value?
I assumed generating lagged values for target_value etc. is exactly what AutoML is supposed to do.

Thanks!

Answer 1

I have encountered the same problem as you on Azure ML... that's why I have decided to use the SmartPredict platform.

The difference is that we are more flexible in terms of modules and custom modules, our modules have more parameters, and we take a use case approach. In addition, we also have Autoflow, which allows us to automatically generate a flowchart. And in terms of IT resources, we can also choose the size and type of resources.

Answer 2

Here is an exemple for forecasting. I think you should specify the models :

automl_config = AutoMLConfig(
    task="forecasting",
    primary_metric="normalized_root_mean_squared_error",
    blocked_models=["ExtremeRandomTrees", "AutoArima", "Prophet"],
    experiment_timeout_hours=0.3,
    training_data=train,
    label_column_name=target_column_name,
    compute_target=compute_target,
    enable_early_stopping=True,
    n_cross_validations=3,
    verbosity=logging.INFO,
    forecasting_parameters=forecasting_parameters,
)

Answer 3

I don't know if you finally found the answer to your question but in case anyone else is looking for a potential solution.

In order to perform a forecast with automl taking into consideration lagged data of the target variable you need to feed context to your forecast.

Here is the documentation: Documentation

And here is the image describing your usecase:

In the documentation, it mentions that you should feed a dataframe with historical values (with the target column filled in) and values you want to predict (with the target column empty) with the following format:

         Timestamp                               Signal
0    2022-08-07T23:00:00Z                     63.16
1    2022-08-08T00:00:00Z                     62.92
2    2022-08-08T01:00:00Z                     62.89
3    2022-08-08T02:00:00Z                     62.79
4    2022-08-08T03:00:00Z                     62.75
..                    ...                       ...
233  2022-08-23T17:00:00Z                       nan
234  2022-08-23T18:00:00Z                       nan
235  2022-08-23T19:00:00Z                       nan
236  2022-08-23T20:00:00Z                       nan
237  2022-08-23T21:00:00Z                       nan