Using an empty aggregate to evaluate sample size
Having all the data made available is usually not a challenge to the data miner—the challenge is having enough of the right data. The data needs to be relevant to the business question, and be from an appropriate time period. Many users of Modeler might not realize that an Aggregate node can be useful even when all you have done is drag it into place, but have given no further instruction to Modeler.
At times data preparation requires the number of records in a dataset to be a data item that is to be used in further calculations. This recipe shows how to use the Aggregate node with no aggregation key and no aggregation operations to produce this count, and how to merge this count into every record ...
Get IBM SPSS Modeler Cookbook now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
