real world objects and relationships database schema (object state) physical model modeling process...
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Real World Objects and relationships
DatabaseSchema
(Object state)
Physical Model
Modeling ProcessConceptual Model
Lists, flow diagrams, etc
Logical ModelDiagram in CASE
Tool
Graphic courtesy of ESRI
Data Model Levels
IncreasingAbstraction
RealityReality
Conceptual ModelConceptual Model
Logical ModelLogical Model
Physical ModelPhysical Model
Human-oriented
Computer-oriented
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 ArcGIS
– input data to the data model
UML NotationZeiler 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
UML Notation ( cont. )
• Abstract class – specify subclasses
underneath– no new instances
• Feature Class– Specify subtypes
underneath
Food
VeggiesMeats
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
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
Type Inheritance
• White triangle– Class B inherits the
properties (attributes, methods) of Class A
– the class street inherits from the class transportation network
• Solid diamond
– the parts and the whole depend on each other
lecture lab
Real World Objects and relationships
DatabaseSchema
(Object state)
Physical Model
Modeling ProcessConceptual Model
Lists, flow diagrams, etc
Logical ModelDiagram in CASE
Tool
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
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/ArcMarine_Tutorial/
• What to turn in:– Screen snapshot of what your ArcMap 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
Raster in
WGS84
extract_west Shifted_west
Output
grid name
Extract_east
Raster in
WGS84
Extract by
Rectangle (2)Output
Extent
Output
Extent
Output
Extent
Shift
Extract by
Rectangle (3)
Extract by
Rectangle
Mosaic
Output
Extent
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
MDeviceIDEastNorthSpeedDirection112.110.88.6121111.312.57.922019.3-3.57.5130114.015.13.923417.312.09.1115
MeasuredData
InstantaneousPoint (ex: CTD)InstantaneousPoint (ex: CTD)
Measurement
XX
YY
TimeStampTimeStamp
MeasuringDevice
MDeviceIDNameTypeMeasurementID1Bob12Poncho13Juanita14Mia25Anita2
MeasuringDevice
MTypeIDVarNameVarDesc VarUnitsMDeviceID1Oranges12Bananas13Cubic cm24Rocks25Limes3MeasuredType
ZZ
MarineIDMarineCodeSeriesIDIPointTypeRecordedTime1AAA1105/04/58 12:00 002BBB1105/04/58 12:30 003CCC1105/04/58 13:00 00
InstantaneousPoints
MeasurementMeasureIDMarineIDZLocXlocYlocServiceTripSeviceDesc11-0.821-1.531-3.542-0.852-1.5
Michael Blongewicz
Objects and Features
• Object (real world)– in ArcGIS 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