EATS 3300 Chapter 5 Questions
1. List and explain types of vector data models.
Types of vector data models are relation-based and object-based. Relation-based vector models are
spaghetti data, topology data, and surface model. Object-based vector models are spatial
features[objects], properties[attributes], and class and class relations. Spaghetti and topology are
relation-based vector models.
In spaghetti vectors, line ends don't meet and there is a lack of connections. It stores data in an
unstructured way. This model stores the name of every object followed by the coordinates the object is
composed of. Every object is described independently of the others. In a spaghetti model, points have
umbers, lines are ordered strings of points that are associated with a searchable point identification
number, and polygons are stored as closed loops of coordinate pairs.
The topology vector model is a field of mathematics that uses diagrams or graphs to study the
arrangements of geometric objects and the relationships between objects. Topological relationships are
invariant under elastic deformation, without tear or merge. Nodes define the two endpoints of an arc,
and then each arc has vertices that compose polygons.
The surface model, is when surfaces are represented. Surfaces involve an elevation value(z) in addition
to (x,y) values.
2. Define and explain relational based vector models, such as spaghetti data, topology data, and surface
Please see above. In a spaghetti vector model, the spaghetti structure is usually derived from manual
digitizing. It is a simple model that stores data in an unstructured way, it stores the name of every object
followed by the coordinates that the object is composed of. Each object is described independently of
3. Please see #1. Vector data consists of points, lines, and polygons.
4. A relational-based vector model is one that whereas an object-based vector model is
5. Please see #1.
6. Common errors in spaghetti vectors are the silver polygon, undershoot, dangling arc, and gap
7. The spaghetti model is simple, easy to understand, and fast for both input and output. It does
however, not include SPATIAL relations with adjacent features and objects, this makes it ineffective for
modelling and analysis.
8. ESRI's shape model(file) stores the geometry of each feature as a shape that contains the coordinates
and links to the attributes. It is a vector data model. 9. Topology is a field of math that uses diagrams or graphs to study the arrangements of geometric
objects and the relationships between them. Topology vector model consis