The SEDRIS Data Representation Model
APPENDIX A - Classes
Enumeration Axis

Class Name: Enumeration Axis

Superclass - <Axis>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class is an <Axis> that uses EDCS Enumerant Codes rather than numerical values as hash marks.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

This class appears on only one page of the DRM class diagram.

Example

  1. Consider a <Property Grid> containing data that varies by ocean bottom material composition. The <Property Grid> therefore has an <Enumeration Axis> of axis_type = EAC_WATER_BODY_FLOOR_MATERIAL_TYPE. The axis_value_array[] contains corresponding values such as EEC_WTRBDFLRMATTY_CLAY_AND_SILT.

  2. Consider a <Property Table> containing data that varies by season of the year. The <Property Table> therefore has an <Enumeration Axis> of axis_type = EAC_SEASON. The axis_value_array[] contains some or all of the values: EEC_SEASON_WINTER, EEC_SEASON_SPRING, EEC_SEASON_SUMMER, or EEC_SEASON_AUTUMN.

FAQs

How should a data provider decide between using an <Enumeration Axis> with one <Table Property Description> per axis entry, and using multiple <Table Property Description> instances, with each <Table Property Description> replacing a value on the <Enumeration Axis>?

If the values on the <Enumeration Axis> represent different values of some variable (days of the week, colours, seasons, states), the data provider should use an <Enumeration Axis> (request a new EAC enumeration if justified). Multiple <Table Property Description> instances should be used when the <Data Table> contains different kinds of dependent data, such as temperature, pressure, and humidity.

Constraints

Component of (two-way)(inherited)

Inherited Field Elements

SE_Element_Type axis_type; (notes)
EDCS_Unit_Code value_unit; (notes)
EDCS_Scale_Code value_scale; (notes)
SE_Short_Integer_Positive axis_value_count; (notes)

Field Elements

EDCS_Enumerant_Code axis_value_array[];

Notes

Fields Notes


axis_type

 This specifies the property being described by the given <Axis>.

value_unit

 This specifies the unit of measurement of the given <Axis>, which
 shall be compatible with the requirements imposed by axis_type.

 If axis_type does not require a unit of measurement (for example,
 if axis_type requires a value type of STRING), then value_unit
 shall be set to EUC_UNITLESS.

value_scale

 This specifies the scale applicable to value_unit.

 If axis_type does not require a unit of measurement (for example,
 if axis_type requires a value type of STRING), then value_scale
 shall be set to ESC_UNI.

axis_value_count

 This is the number of "hash marks" along the given <Axis>.
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Last updated: May 15, 2003 Copyright © 2003 SEDRIS™