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Aggregate Meta Data

Synopsis​

Aggregates numerical meta data entries of a set of documents. The result will be added as new meta data to each of the documents.

Description​

This operator iterates over all documents connected to the input port extender. Collections of Documents will be unfolded and each containing document will be treated as if not being part of a collection. The numeric values of the meta data specified by the source meta data key parameter will be aggregated with the aggregation function selected by the user. The aggregated value will be written into all documents with the target meta data key. All documents will be delivered as single collection, regardless if forwarded as part of a collection or as single document.

Input​

documents​

The documents port.

Output​

document collection​

The document collection port.

Parameters​

Source metadata key​

Specifies the key of the metadata that will be aggregated.

Result metadata key​

The aggregated value of the documents meta data specified by the source key will be saved under this meta data key. The key will become the name of the attribute after document processing.

Aggregation​

This specifies how the tokens' lengths are aggregated to one single number.