Class Name: Table Property Description

Superclass - <SEDRIS Abstract Base>

Subclasses

Definition

An instance of this DRM class specifies a cell data element within a <Data Table> by providing

1. an EAC, SE_Index_Code, or SE_Variable_Code, identifying the meaning of the cell data element,

2. a value_type that specifies its storage type,

3. an EUC and ESC that together specify the scaled unit of measurement.

Additional information about the cell property being described, where such information is to be applied throughout the scope of the <Data Table>, such as sentinel values and tolerances, is specified by attaching <Property Characteristic> components to the applicable <Table Property Description>(s).

Primary Page in DRM Diagram:

• 6

Secondary Pages in DRM Diagram:

Example

1. Consider a <Property Grid> instance containing sound speed data for a body of water. For each spatial location in the grid, the corresponding cell in the <Property Grid> instance specifies the properties of EAC_SALINITY, EAC_MEAN_WATER_BODY_TEMPERATURE, and EAC_WATER_BODY_SOUND_SPEED at that location.

   

FAQs

Why is the value_type field needed?

The storage type of each cell data element shall be specified, and each cell data element shall be allowed to specify its own storage type. This means that the storage type information cannot be stored in the <Data Table>'s own fields, but shall be specified at the <Table Property Description> level.

Unlike <Property Value>, which contains a complete EDCS_Attribute_Value, <Table Property Description> only needs to to specify the storage type without a value being stored, since the values being described are the cells of the <Data Table>, rather than any part of the <Table Property Description> itself.

What is the purpose of the component_data_table_ecc field and the optional <Property Value> components?

Consider a <Data Table> instance with more than one <Table Property Description> supplying the same SE_Index_Code as a meaning, where that meaning is that each such <Table Property Description> acts as a signature element to reference other <Data Tables>.

In these cases, the component_data_table_ecc, possibly elaborated by optional <Property Values>, is needed to distinguish index values in any given cell.

See <Classification Data> and the <<Index Codes within Tables>> constraint for further information.

Constraints

• <<Publishable Object>>

Composed of (two-way)

• zero or more <Property Characteristic> instances
• zero or more <Property Value> instances (notes)

Component of (two-way)

• one or more <Data Table> instances

Inherited Field Elements

Field Elements

Notes

Composed of Notes

Property_Value

 These components are provided only when the given
 <Table Property Description> serves as an index into another
 <Data Table>, specifically, when the target <Data Table>'s
 <Classification Data> is elaborated by <Property Value> components.

 When such elaboration is present in the target, the
 <Property Value> components of this <Table Property Description>
 shall match those in the target.

Fields Notes

meaning

 The meaning field specifies the meaning of the given
 <Table Property Description> instance.

value_unit

 The value_unit field specifies the unit of measurement of the given
 <Table Property Description> instance.

value_scale

 The value_scale field specifies the scale applicable to value_unit.

value_type

 The value_type field specifies the storage type of the given
 <Table Property Description> instance.

component_data_table_ecc

 The component_data_table_ecc field specifies the ECC used to identify
 the table type of a component or library <Data Table> instance.  It
 is used only if the given <Table Property Description> instance is
 describing an index that refers to a <Data Table> instance.

 This, in turn, is only the case if
    meaning = { SE_ELEM_CODE_TYP_INDEX,
                {SE_INDEX_CODE_DATA_TABLE_COMPONENT }}
 or
    meaning = { SE_ELEM_CODE_TYP_INDEX,
                {SE_INDEX_CODE_DATA_TABLE_LIBRARY }}