3.1 Infrastructure standards
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The application pro gram used far the route computation requires the data of the
GIS. The data are partitioned into the dataset and the metadata.
The program involved falls in the category of geographie information services.
This service is a software pro gram that uses the data supplied in the dataset and in
the metadata.
The dataset contains the cities and the roads, and the underlying geometries such
as points, lines, and coordinates. The cities and roads are called geographie features.
A specific city A and another city Bare called feature instances. The points and lines
are called spatial objects and the coordinates are referred to as DirectPositions.
The metadata contains attributes like road condition and speed limit. In this example one metadata exists for one feature instance of a road.
The most frequently used type of UML-diagram is a class-diagram which consists
of classes and their interrelations. A class may be anything that the developer has defined to have common properties. In this example the first case three classes have
been defined:
• City
• Road
• RouteFinder
The class RouteFinder may be called a tide class of the classes Road and City.
The class RouteFinder can also be called parent-class whereas the other two are the
children-classes.
Later in the development the model might have to be refined. Let us assume that
different types of computations are required far routes using the main roads and the
local roads. For this purpose, the class Roads would be split into subclasses according to the road classification. As far as possible, properties like the length of the
road would be kept in the super class as feasible. Only the properties that are unique
to a subclass such as the maximum speed or winter closure have to be placed there.
A UML class has a name, a set of attributes, a set of operations, and constraints.
In our example, the class names are City and Road. It is required that a class name is
unique in a model. Thus, in larger models the class name is often a combination of
the identification of the sub-model and the name like FR_City and FR _ Road, where
FR stands far the program's purpose "fastest route". Class names must start with an
uppercase character.
The second case of the model that includes the main road and the local road is
shown in figure 3.3.
Attributes are values that are related to the class. In our example, the length of the
road is an attribute. Another attribute may be a status tag like "road open" or "road
closed".
Operations are functions that are related to the class. Many classes have the two
rather basic functions "setAttributes" and "getAttributes" that allow writing and
reading of the attributes of the class. Another operation that might make some sense
in our example could answer the question of whether the whole length of the road
can be travelled within one hour going at a speed of 80 km/ho The funetion would
address the attributes length and availability, and return the result.
61
The application pro gram used far the route computation requires the data of the
GIS. The data are partitioned into the dataset and the metadata.
The program involved falls in the category of geographie information services.
This service is a software pro gram that uses the data supplied in the dataset and in
the metadata.
The dataset contains the cities and the roads, and the underlying geometries such
as points, lines, and coordinates. The cities and roads are called geographie features.
A specific city A and another city Bare called feature instances. The points and lines
are called spatial objects and the coordinates are referred to as DirectPositions.
The metadata contains attributes like road condition and speed limit. In this example one metadata exists for one feature instance of a road.
The most frequently used type of UML-diagram is a class-diagram which consists
of classes and their interrelations. A class may be anything that the developer has defined to have common properties. In this example the first case three classes have
been defined:
• City
• Road
• RouteFinder
The class RouteFinder may be called a tide class of the classes Road and City.
The class RouteFinder can also be called parent-class whereas the other two are the
children-classes.
Later in the development the model might have to be refined. Let us assume that
different types of computations are required far routes using the main roads and the
local roads. For this purpose, the class Roads would be split into subclasses according to the road classification. As far as possible, properties like the length of the
road would be kept in the super class as feasible. Only the properties that are unique
to a subclass such as the maximum speed or winter closure have to be placed there.
A UML class has a name, a set of attributes, a set of operations, and constraints.
In our example, the class names are City and Road. It is required that a class name is
unique in a model. Thus, in larger models the class name is often a combination of
the identification of the sub-model and the name like FR_City and FR _ Road, where
FR stands far the program's purpose "fastest route". Class names must start with an
uppercase character.
The second case of the model that includes the main road and the local road is
shown in figure 3.3.
Attributes are values that are related to the class. In our example, the length of the
road is an attribute. Another attribute may be a status tag like "road open" or "road
closed".
Operations are functions that are related to the class. Many classes have the two
rather basic functions "setAttributes" and "getAttributes" that allow writing and
reading of the attributes of the class. Another operation that might make some sense
in our example could answer the question of whether the whole length of the road
can be travelled within one hour going at a speed of 80 km/ho The funetion would
address the attributes length and availability, and return the result.