The Measures of the model are the different options available to the user for analyzing values stored in the cube. They represent the quantity of a given element of the Dimension and can be obtained directly from the Data Source or calculated from them.
Depending on the cube being analyzed, Measures can include a diverse range of concepts such as prices, physical units, quantity of invoices, and average volume. You can also define Measures representing value's scales, or the number of times a given value appears.
If there are hierarchical Dimensions in the Model, each Measure indicates what the corresponding Aggregate mode is; that is, how the value of the highest element of the hierarchy should calculate, based on the value of the lowest level.
There are two types of measures:
- Basic: Measures taken directly from a data sources field
- Derived: Measures calculated from basic measures through the application of calculation expressions
You can use the Measure Format dialog in the General pane to format the results, specifying for example, the number of decimals, alignment and color of negative values, currency symbols, etc. The end-user has the ability to modify this predefined values from the O3 Browser.
Basic Measures
Basic measures are those values specified in the data sources as another field of each record (or as a Virtual Field. See About Virtual Fields). Each record coming from a source has to provide the value for this measure.
The dimensions hierarchical structure necessitates the analysis of measures at different levels of detail. To indicate how the values for a level's register accumulate, you specify an aggregation mode. O3 automatically performs the aggregation.
Some measures require a special accumulation method over date dimensions. For example, in the case of a company's inventory measure, its value in units of different months should not be added up to obtain the value for the whole year's inventory. However, it may be necessary to include other dimensions such as the classification of products in line and families in the inventory analysis cube. To resolve this, O3 allows you to declare a measure's dependency on a date dimension.
Derived Measures
Derived measures are values calculated using basic measures in expressions.
These measures are calculated in each level of the dimensions hierarchies from the basic measures. This means you do not need an aggregation mode definition.
Calculations are as follows for each level of the hierarchy:
- The basic measures values are calculated, applying the aggregation modes
- The derived measures are calculated from the basic measures
You can define derived measures in the following ways:
Predefined |
Use predefined O3 expressions with 2 basic measures. Predefined operators are sum, difference, quotient, multiplication and percentage. |
Date Accumulation |
Defines an accumulation of a basic for a date dimension. It is possible to define the highest accumulation level in the date dimension (yearly, quarterly, monthly, etc.) |
Count Distinct |
Counts the different elements in a given level of a dimension based on a basic measure. |
Other Expression |
Enter an expression using any number of basic measures, and any operators and functions in the Operators and Functions for Expressions and Virtual Fields table. |
Statistics |
Defines the measure using statistical operations such as Population Variance or Quadratic Mean. |