Licensing optionsfor this format begin with FME Professional Edition.
The Canadian Council on Geomatics Interchange Format (CCOGIF) ASCII reader provides FME with access to the contents of a CCOGIF dataset stored in ASCII format in a single disk file. The structure of this file is discussed in Canadian Council on Geomatics’ document,Standard File Exchange Format for Digital Spatial Dataversion #2.3, published October 1994.
的CCOGIF格式，数据交换格式，提供了在其中以表示数据模型非常一般的平台。FME访问CCOGIF文件的单个记录在一个非常低的水平，仅涉及的这些记录的内容最少的解释。这使得FME处理几乎任何数据与CCOGIF标准编码，但需要一个较为复杂的映射文件，以充分利用这些数据。
概观
The CCOGIF disk file consists of a series of logical records. Each of these records either describes元数据which is information about the data contents or structuring, orentity datawhich are geometric features.
所述CCOGIF文件描述了单个数据量，即组空间数据到datasets,data groups, anddata themes。一个CCOGIF卷包含一个或多个数据集。单个CCOGIF数据集包含一个或多个数据组，并且单个数据组包含一个或多个数据的主题。
At the highest level of grouping, the CCOGIF dataset – not to be confused with FME's concept of a dataset which is referred to as an FME dataset for the remainder of this chapter – groups the entity data by geographic region, such as a map sheet. In other words, all geographic data contained in a single CCOGIF dataset are somehow geographically related. All entity data within a CCOGIF dataset are measured in a single coordinate system.
Each data group provides some conceptual grouping of geographic entities. The criteria of this grouping are entirely data-dependent and are not constrained by the CCOGIF standard. This grouping is somewhat analogous to FME's notion of a feature type. For example, a CCOGIF dataset might contain the data groupsHighway,Bridge, andIntersection。
The data within a single CCOGIF data group is divided into data themes. Each data theme represents a certain entity type: point, line, or area. The definition of a theme includes a list of data attributes. All attributes are defined on every entity record within the theme. A single data group may contain more than one theme of a given type – for example, two point themes. The themes are always ordered so that point themes come first, then line themes, and finally area themes.
阅读器概述
For the most part, the CCOGIF reader simply returns a feature to represent each record it encounters in the CCOGIF file. The reader does not have any requirement for definition statements.
The feature type of a feature returned from the CCOGIF reader depends on whether the feature represents metadata or entity data. Features that represent metadata records are returned with a feature type ofCCOGIF_METADATA, whereas features that represent entity records are returned with a feature type dependent on the CCOGIF data group and theme within that data group. The feature type will have the format<组名> _
有不同的方法来生成工作区读CCOGIF数据。所产生的工作区通过多个工厂的运行特性，所以在自动生成的工作区使用的特征类型的实际名称将取决于所使用的方法和可能不对应于从读取器本身返回的特征类型。