representing_numeric

Template:— representing_numeric_property (rep_num)

Date: 2008/01/21 08:52:14
Revision: 1.20

Cover Contents Description Model diags.Input params.Ref. params.Instantiation path Instance diags.Characterizations Issues

This section specifies the template representing_numeric_property.

NOTE An explanation of a template and the associated instantiation path is provided in the Template overview section.

Description

This template describes how to represent a single numerical value with unit for any property. It provides a context for the value, and the representation may be further characterized by assigning time and organization.

EXAMPLE The number of hours taken to perform some action.

Model diagrams

The EXPRESS-G diagram in Figure 1 shows the templates and EXPRESS entities that are required to represent the template "representing_numeric_property". The text highlighted in blue shows the template parameters.

Figure 1 — An EXPRESS-G representation of the Information model for representing_numeric_property

The graphic for the template to be used in other EXPRESS-G diagrams is shown in Figure 2 below.

Figure 2 — The graphical representation of representing_numeric_property template

Input parameters

The following input parameters are defined for this template:

value (Type= 'TYPE (any_number_value)' )

The value of the property. The datatype is always 'any_number_value' and should not be registered together with the value, i.e. enter the value as a number, without datatype.

unit (Type='CLASS')

The class name of the unit in which the value is expressed.

The following classes and their sub-classes can be used:

classifications: "Context_dependent_unit" (urn:plcs:rdl:std:Context_dependent_unit)

unit_ecl_id (Default=urn:plcs:rdl:std,Type='URN')

The identifier of the External_class_library storing the definition of the class referenced by the parameter @unit.

si_unit (Default=false,Type='BOOLEAN')

Value should be set to true if the unit is a SI base unit defined by ISO, i.e. kilogram (kg) for Mass, second (s) for Time, metre (m) for Displacement, ampere (A) for Electrical current, kelvin (K) for Temperature, mole (mol) for Amount of substance, and candela (cd) for Luminous intensity. If this is not the case it should be set to false.
Note that the representation of true and false depends on exchange format. In Part 11 (a STEP file) true is represented by the string ".T.", and false by ".F.", while in Part 28 (XML) they are represented by text strings "true" and "false".

context (Type='CLASS')

The name of the class being used to classify the representation context (Numerical_representation_context) of the property.

The following classes and their sub-classes can be used:

classifications: "Numerical_representation_context" (urn:plcs:rdl:std:Numerical_representation_context)

context_ecl_id (Default=urn:plcs:rdl:std,Type='URN')

The identifier of the External_class_library storing the definition of the class referenced by the parameter @context.

Reference parameters

The following reference parameters are defined for this template:

representation(Type='ENTITY (Property_value_representation)')

Allow the Property_value_representation entity instantiated in this path to be referenced when this template is used.

Note: The Property_value_representation entity can be referenced in a template path by:

%^target = $representing_numeric_property.representation%

where target is the parameter to which the Property_value_representation is bound.

item(Type='ENTITY (Numerical_item_with_unit)')

Allow the Numerical_item_with_unit entity instantiated in this path to be referenced when this template is used.

Note: The Numerical_item_with_unit entity can be referenced in a template path by:

%^target = $representing_numeric_property.item%

where target is the parameter to which the Numerical_item_with_unit is bound.

representation_context(Type='ENTITY (Numerical_representation_context)')

Allow the Numerical_representation_context entity instantiated in this path to be referenced when this template is used.

Note: The Numerical_representation_context entity can be referenced in a template path by:

%^target = $representing_numeric_property.representation_context%

where target is the parameter to which the Numerical_representation_context is bound.

Uniqueness constraints

The following parameter combinations specify a uniqueness constraint:

Unique constraint: Unique Numerical_representation_context

Each instance of the entity (Numerical_representation_context) within the data set shall be uniquely identified by a combination of the following parameters on this template (representing_numeric_property) namely: context, context_ecl_id.
The instance is referenced by the following template parameter: representation_context.

Instantiation path

The instantiation path shown below specifies the entities that are to be instantiated by the template.

A description of templates and the syntax for the instantiation path is provided in the Templates Help/Information section.

-- Instantiate Property_value_representation entity
Property_value_representation

-- Set the Property_value_representation attributes id, name and description to be ignored
Property_value_representation.id = '/IGNORE'
Property_value_representation.name = '/IGNORE'
Property_value_representation.description = '/IGNORE'

-- Bind the Property_value_representation to the parameter ^representation.
-- The parameter is a reference parameter so the Property_value_representation
-- entity can be referred to when this template is used.
%^representation = Property_value_representation%

-- Instantiate Numerical_representation_context
Numerical_representation_context

-- Bind the Numerical_representation_context to the parameter ^representation_context.
-- The parameter is a reference parameter so the Numerical_representation_context
-- entity can be referred to when this template is used.
%^representation_context = Numerical_representation_context%

-- assign Property_value_representation to Numerical_representation_context
^representation.context_of_items -> ^representation_context

-- Set the Numerical_representation_context attributes id and kind to be ignored
Numerical_representation_context.id = '/IGNORE'
Numerical_representation_context.kind = '/IGNORE'

-- Assign reference data for kind of Numerical_representation_context
/assigning_reference_data(
    items=Numerical_representation_context,
    class_name=@context,
    ecl_id=@context_ecl_id)/

-- Instantiate template representing_numerical_item
-- for value and unit
/representing_numerical_item(
    value= @value,
    unit= @unit,
    unit_ecl_id= @unit_ecl_id,
    si_unit= @si_unit)/

-- Bind ref param ^item in just instantiated template
-- representing_numerical_item to ref param ^item in this template,
-- and point attribute Value_range.upper_limit to it
%^item = $representing_numerical_item.item%
Property_value_representation.items -> ^item

The following entities are instantiated with attributes as specified:

Entity in path	Value	Inherited from
Property_value_representation.id	'/IGNORE'	Representation.id
Property_value_representation.name	'/IGNORE'	Representation.name
Property_value_representation.description	'/IGNORE'	Representation.description
Numerical_representation_context.id	'/IGNORE'	Representation_context.id
Numerical_representation_context.kind	'/IGNORE'	Representation_context.kind

Instance diagrams

The instance diagram in Figure 3 shows an example of the EXPRESS entities and templates that are instantiated by the template:

/representing_numeric_property(value='any_number_value(3.5)', si_unit='false', unit_class_name='Hour', unit_ecl_id='urn:plcs:rdl:std', rep_class_name='Contractor_provided', rep_ecl_id='urn:plcs:rdl:sample')/

(an illustration of the consolidated representing_numeric_property template is shown in Figure 4 below.)

Note that the templates assigning_time and assigning_organization are used in the diagram. Namely:

@66 /assigning_time(date_class_name='Date_actual_creation', date_ecl_id='urn:plcs:rdl:std', year='2005', month='10', day='7', hour='11', sense='behind', hour_offset='-1', items='#1')/

and:

@77 /assigning_organization(org_id='BestBike Ltd', org_id_class_name='Organization_name', org_id_ecl_id='urn:plcs:rdl:std', org_assgn_class_name='Creator_of', org_assgn_ecl_id='urn:plcs:rdl:std', items='#1')/

Figure 3 — Entities instantiated by representing_numeric_property template

The instance diagram in Figure 4 shows the graphic symbol for the template that is to be used in other instance diagrams. The example template is:

Figure 4 — Instantiation of representing_numeric_property template

Characterizations

The following section details how the representing_numeric_property template can be optionally characterized by assigning other constructs to it. These are characterizations commonly applied to the template. The ISO 10303-239 EXPRESS model may enable other assignments to the entities instantiated by the template.

The EXPRESS-G diagram in Figure 5 shows the possible characterizations of the template "representing_numeric_property".

Figure 5 — Characterizations for representing_numeric_property template

The following characterizations may apply:

Characterization Assigning date and time

NOTE this characterization is optional.

A date (and time) can be associated with the assignment of property value representation by using the template assigning_calendar_date, or assigning_time (recommended since it gives the additional level of detail of hours and optionally minutes and seconds).

Figure 6 — Characterization by date and time of representing_numeric_property template

A creation date and time is commonly assigned to the template representing_numeric_property.

The date of creation of the property value representation is represented by using the template assigning_time to assign a date (and hour) to Property_value_representation. The date assignment is classified as: "Date actual creation" (urn:plcs:rdl:std:Date actual creation) to indicate that it is the date when the property value representation was actually created. This is illustrated in Figure 5 and instantiated in Figure 6.

Other dates may be assigned instead of "Date_actual_creation".

Characterization Assigning organization

NOTE this characterization is optional.

An organization (or a person in an organization) can be associated with the property value representation by using the template assigning_organization, or assigning_person_in_organization.

Figure 7 — Characterization by organization of representing_numeric_property template

A common role in which an organization is assigned to a property value representation is as a "Creator of" the representation. The creating organization is represented by using the template assigning_organization assigned to Property_value_representation. The assignment of the organization (Organization_or_person_in_organization_assignment) is classified as: "Creator of" (urn:plcs:rdl:std:Creator of) to indicate that this organization created the property value representation. This is illustrated in Figure 5 and instantiated in Figure 7.

Other roles of an organization with regard to a property value representation may be assigned instead of "Creator_of".