The entity features are the features that represent the entities of the CCOGIF dataset. When reading CCOGIF data, an entity feature will have a feature type of <data_group>_<theme_index>, where:
<data_group> is the name of the data group, taken from the most recent DGHR metadata record. All special characters—such as spaces, colons, etc.—are replaced with underscores.
<theme_index> is the index within the data group of the theme containing the entity. The themes are numbered sequentially within their data group. The first theme in each data group is number 1.
Entities may be described in a CCOGIF file as a pair of records. Each entity has a fixed length record and, optionally, a variable-length record. The fixed length portion contains information, such as an ID number, a point's location, a line's topological information, a feature code, and attribute values. In other words, the data present for all entities in the theme.
The variable-length portion contains the data that varies in size between entities within a given theme and may or may not be present for a given entity. It contains, for example, a list of lines attached to a point entity, the coordinates defining a line, or the list of identifiers of lines defining an area's boundaries.
FME's entity features combine the contents of the fixed length and variable length records for a particular entity into a single FME feature.
All entity features have the following attributes defined on them:
|
Attribute Name |
Description |
Type |
|
ccogif_record_code |
Record code, constant PFLR for point entities, LFLR for line entities, AFLR for area entities. |
char(4) |
|
ccogif_data_coll_md_ptr |
Data collection metadata pointer (reference number of EMDR corresponding to data collection). |
int(16) |
|
ccogif_data_rev_md_ptr |
Data collection metadata pointer (reference of EMDR corresponding to data revision or validation). |
int(16) |
|
ccogif_prim_feat_code |
Primary feature code for the entity. |
char(12) |
|
ccogif_data_group_name |
Name of the data group containing the entity. |
char(40) |
|
ccogif_data_theme_id |
Index of the data theme within the data group. |
int(16) |
Each specific type of entity has additional attributes to describe the entity and are listed in the sections that follow.
In addition to the standard attributes, each entity feature also has values for all attributes listed in its data theme's ADR.