Modeling Process Conceptual Model Lists flow diagrams etc

Modeling Process Conceptual Model Lists, flow diagrams, etc Real World Objects and relationships Logical Model Diagram in CASE Tool Physical Model Database Schema (Object state) Graphic courtesy of ESRI

Data Model Levels Humanoriented Reality Conceptual Model Logical Model Computeroriented Physical Model Increasing Abstraction

Steps in Data Modeling (1) Conceptualize the user's view of data – what are the basic features needed to solve the problem? (2) Select the geographic representation – points, lines, areas, rasters, TINs (3) Define objects and relationships – draw a UML diagram, specify relationships, “behaviors” (4) Match to geodatabase elements – Refine relationships, “behaviors” (5) Organize geodatabase structure, add data

UML ( cont. ) • Diagrammatic notation = “visual language”. . . • For constructing a data model • Drawings, relationships constructed in Visio • Tools to input a drawing to Arc. GIS – input data to the data model

UML Notation Zeiler pp. 97 -99 • a class is shown as a box • top part: name of class • lower part: attributes • methods associated with the class • lines connect boxes, indicate relationships

Graphic courtesy of Maidment et al. , Arc. Hydro team

UML Notation ( cont. ) • Abstract class Food Veggies – specify subclasses underneath – no new instances • Feature Class – Specify subtypes underneath Meats

Relationships • Links between classes, shown as lines • One to one • One to many • Many to many

Relationships (cont. ) • 1: 1 - solid line – one record in Class A linked to one record in Class B • “is married to” • the class of state capitals linked to the class of states • 1: n - solid line with * at one end – one record in Class A linked to any number of records in Class B • "owns" • the class of states linked to the class of area codes

Graphic courtesy of Maidment et al. , Arc. Hydro team

Relationships (Arc Marine example)

Relationships (cont. ) • m: n - solid line with * at both ends – any number of records in Class A linked to any number of records in Class B • "has visited” • "was never married to" • the class of mountain lions linked to the class of wilderness areas

Study Area Image courtesy of Dan Fornari, Woods Hole Oceanographic Institution

Type Inheritance • White triangle – Class B inherits the properties (attributes, methods) of Class A – the class street inherits from the class transportation network lecture lab • Solid diamond – the parts and the whole depend on each other

Graphic courtesy of Maidment et al. , Arc. Hydro team

Modeling Process Conceptual Model Lists, flow diagrams, etc Real World Objects and relationships Logical Model Diagram in CASE Tool Physical Model Database Schema (Object state) Graphic courtesy of ESRI

Steps in Data Modeling (1) Conceptualize the user's view of data – what are the basic features needed to solve the problem? (2) Select the geographic representation – points, lines, areas, rasters, TINs (3) Define objects and relationships – draw a UML diagram, specify relationships, “behaviors” (4) Match to geodatabase elements – Refine relationships, “behaviors” (5) Organize geodatabase structure, add data

or XMI file

Using a Design Template Schema Wizard reads repository or XMI to create a geodatabase

or XMI file

Steps in Data Modeling (1) Conceptualize the user's view of data – what are the basic features needed to solve the problem? (2) Select the geographic representation – points, lines, areas, rasters, TINs (3) Define objects and relationships – draw a UML diagram, specify relationships, “behaviors” (4) Match to geodatabase elements – Refine relationships, “behaviors” (5) Organize geodatabase structure, add data – e. g. , Marine Data Model tutorial

Arc Marine Data Model Exercise • Exercise and data at dusk. geo. orst. edu/djl/arcgis/Arc. Marine_Tutorial/ • What to turn in: – Screen snapshot of what your Arc. Map session looks like at the end of Section 4 (including dynseg referencing) – Answers to 2 simple questions at end of Section 4 (which cruise? which vehicle? ) – Can put all of the above in a single MS-Word document, labeled with your NAME please! • Due in Dropbox, Apr. 29, 6: 00 p. m.

Geoprocessing Models Model Builder diagrams for workflow Extract by Rectangle Extract_east Output Extent Raster in WGS 84 Extract by Rectangle (2) Output Extent extract_west Extract by Rectangle (3) Shift Output grid name Shifted_west Mosaic Output Extent Raster in WGS 84

Resulting Analysis - Arc. Hydro From Arctur and Zeiler, Geodatabase Design, ESRI Press.

Gateway to the Literature • Arctur, D. and Zeiler, M. , 2004, Designing Geodatabases, ESRI Press • • • Lowe, J. W. , 2003. Flexible data models strut the runway. Geospatial Solutions, 13(2): 44 -47. Maidment, D. R. , 2002. Arc Hydro: GIS for Water Resources, ESRI Press, 203 pp. w/CD. Li, X. and M. E. Hodgson, 2004. Vector-field data model and operations. GISci. Rem. Sens. , 41(1): 1 -24. • Wright, D. , Blongewicz, M. , Halpin, P. , and Breman, J. , Arc Marine: GIS for a Blue Planet, Redlands: ESRI Press, 2007. – In the classroom or dusk. geo. orst. edu/djl/arcgis/book. html

Instantaneous. Point (ex: CTD) Michael Blongewicz X Instantaneous. Points Time. Stamp Y Measurement Measuring. Device Z Measured. Type Measured. Data

Objects and Features • Object (real world) – in Arc. GIS an object is non-spatial – it is NOT a point, line, or area – it has no geographic location – it has no shape attribute in its table – Drainage network, ship, vehicle, … customer, lake, house, etc. • Feature (spatial context) – an object that has geographic location – a point, line, area, TIN, raster