The Spectre measures process spans the Transform and Organize stages of the measures process flow. A measures script can be specified after the source data has been prepared and built into standardized data sets and the measures are defined. The measures script identifies any dimensions that need to be mapped, the data sets to be created from each source, and the summaries to be used for each measurement.
When a measures script is run, the source data is broken up and squashed into smaller tables in order to separate the data by data-source and dimension-mapping. For example, 'Admit Date' can become 'Date' for the admit-based summaries. That is the core function of the squash step. The Spectre engine uses the measures script to process the specified measures by using the summaries available from the data sets. Spectre also removes unused data and renames and copies some columns so that they are consistent for later steps.
The measures process also attaches some properties to the summaries indicating the data source, any dimension mapping, and what expressions were used to compute them in the squash.
The Spectre measures command generates the following directories and files within the project:
- data-sets-cplans/*.cplan—One cPlan per data set as specified in the measures script.
- measure-cplans/*.cplan—One cPlan per measure, with normalized calc names (such as "Measure Value"), as specified in the measures script.
- measures-data/*.cbase—One cBase per data set as specified in the measures script. These are the main measures tables, with all the requested dimensions and all the components of the measures built into them.
- all-measures.cplan—A cPlan that defines calcs for all of the measures. This cPlan is for the Matrix Portlet in DivePort, or any other displays that display one or more specific measures.
- measures-data.cplan—A simple cPlan that pulls together each of the cBases in measures-data.
- measure-info.cbase—A table with one row per measure. This cBase is for making QuickViews in Markers and QuickView Sets for dives, so displays can be parameterized by the measure key.
- one-measure.cplan—A master cPlan that delegates to one of the per-measure cPlans, based on the value of a "Measure Key" parameter.
See also: