Signal Aliasing

Use signal aliasing to ensure every dataset has a unified set of output signals. Alias signals are created by looking at the existing dataset signals, finding the first one that matches the output signals' rule.

Some datasets may contain a Speed signal, while others have a Velocity signal, and some may even have both. To ensure that each dataset contains a given set of signals, you can define aliasing rules. These rules allow you to standardize signal names across diverse datasets.

Aliasing rules can be set in the general settings tab and are assigned to one, some, or all datastreams.

At the end of import, Marple DB will run each aliasing rule that applies to the datastream. During this step, the following things happen:

• If a signal with the rule's specified output name already exists in the dataset, the rule is skipped for that signal.

• Else, iterate over the reference signals, when the dataset contains a signal with this name, it becomes the reference signal.

• A new alias signal with the specified name is created with the data of the reference signal.

• When no matching reference signal is found, skip the rule.

Creating new Rules

On creating a new rule, the following options are available

• Alias: The name of the new signal.

• Reference signals: a hierarchical list of signal names that can be used as reference signal. The first signal in this list that exists in the dataset will be used.

• Description: Description for the newly created signal.

• Copy metadata: whether the metadata of the reference signal should be copied to the new signal. The metadata is always extended to indicate which signal was used as reference signal.

• Datastreams: a selection of datastreams that will use this rule. If you select "Apply to all datastreams", the rule will also apply to datastreams that are created in the future.

Apply Signal Aliasing

All relevant aliasing rules are applied automatically to each new dataset you import. When you define a new rule and you want to apply it to datasets you already imported before, there are two options:

• 1 individual dataset: select the dataset & click the "Redo aliasing" button

• An entire datastream: under configure > Aliasing signals, click the "Rerun all rules" button, this will rerun all rules on all datasets in the datastream. This might take a while so make sure you define all the relevant rules so you can run them all at once.

Signal Aliasing in Marple Insight

Signals that are created via an aliasing rule have an extra Reference Signal metadata field that indicates which signal was used for its creation.

Signal aliasing is especially powerful to ensure your Marple Insight functions & projects work for all your datasets, irrespective of where they come from and what signals are available in there.