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Extra Materials. Introduction to ArcWorkstation. What’s it look like?. Traditionally a UNIX based “command line interface” package… Ran on UNIX machines. You typed in commands, and it showed you the results in another simple window. What’s ArcWorkstation made up of?.

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extra materials

Extra Materials

Introduction to ArcWorkstation

what s it look like
What’s it look like?
  • Traditionally a UNIX based “command line interface” package…
    • Ran on UNIX machines.
    • You typed in commands, and it showed you the results in another simple window.
what s arcworkstation made up of
What’s ArcWorkstation made up of?
  • Made up of separate modules that communicate with each other. The command line interface is…

Arc: core application for doing analysis, and using “workspaces” where all the files are kept for each

project.

ArcEdit: for editing maps interactively.

ArcPlot: for neat plotting of maps.

ArcTools: Pre-made AML scripts

Grid: for working with image files/raster data.

(Might also see on older systems: ArcTIN: 3D work; ArcPress: printing; ArcStorm: multiuser databases; ArcNetwork: networks).

what is arcworkstation
What is ArcWorkstation?
  • You can think of it as two main bits…
    • ARC – the starting program where most stuff is done.
    • INFO – a database, which holds tables of related information, all tagged with a geographical location.
    • Lets you analyse the database data using a map interface, and display the results as a map.
why bother with it
Why bother with it?
  • Because:
    • ArcGIS 8/9.x doesn’t have the functionality of ArcWorkstation, and plenty of places still use it.
    • There is still a lot of use of legacy AML code.
    • There is still a lot of data floating around in Coverages.
  • We’ll teach you enough to understand how it works and give you a foundation to work from if you come across it.
the arcinfo data model
The ArcInfo Data Model
  • Store all the same types of features in one file using x,y coordinates…
    • i.e. all the point features in one file, all the line features in another file, and all the associated non-location data in yet another file.
  • Makes storage and handling easier.
  • Makes analysis easier.
  • The filenames show what kind of data they hold.
    • e.g. Label Points are stored in a LAB (lab.adf) file.
storing vector data
Storing Vector data
  • The files hold coordinate data and Feature Numbers that are assigned sequentially to Features in the file.
slide9
Tics
  • Tics – geographical control points used to register (overlap) different datasets, and transform (eg. put in a new projection scheme) the data.
  • For example, you might mark in known locations on two datasets, usually at the data edges, as Tics.
  • Stored in a TIC file (tic.adf).
slide10
Arcs
  • Arcs - stored in an ARC file (arc.adf).
  • A point where an Arc changes direction is called a “Vertex”.
  • The start and ends of Arcs, and the crossing point between two Arcs, are called “Nodes”.
  • The ARC file stores each Vertex and Node as an x,y coordinate.

Data can be assigned to Nodes

polygons
Polygons
  • An area - can also have “islands” inside, that cut out inner areas.
  • Made from one (or more) Arcs.
  • The end Node is the same as the starting one.
  • Each also has a Label Point (x,y) associated with it, stored in a LAB file.

+42

polygon arc list
Polygon-Arc List
  • The Polygon-Arc List file (pal.adf) stores which Arcs make up each Polygon. That way we don’t need to store the Arc coordinates again.

ARC

PAL

#1

#2

+23

#3

polygon arc list1
Polygon-Arc List
  • The outside or “Universe” Polygon is always feature number 1, ie. first in the PAL file.
  • Islands start with a zero, followed by the Arcs.
topology
Topology
  • Analysis we might want to do…
    • “How do I move from Arc to Arc to get from A to B fastest?”
    • “If I leave Polygon A going north, which Polygon do I enter?”
  • To do these analyses we need some notion of Topology, ie. the spatial relationships between features.
topology in arcinfo
Topology in ArcInfo
  • Three ways topology is defined in ArcInfo…
    • Arcs connect at Nodes.
    • Arcs have direction, and therefore a left and right side.
    • Arcs that connect to surround an area make a Polygon.
how topology is stored
How Topology is stored

Note that polygons are listed

clockwise in the PAL, with minus figures for reverse direction Arcs.

  • Stored in the files.

N2

PAL

+23

N1

N3

ARC/ATT

feature attributes
Feature Attributes
  • Info stores information about each feature in a Feature Attribute Table using the Feature Number to match the attribute data to the coordinates in the other files in a one-to-one relationship. Each data type has its own table type.
  • Each feature will also have a unique User Defined ID kept in its table in addition to its Feature Number.

PAL

FAT

types of feature attribute table
Types of Feature Attribute Table
  • Label Points / Polygons – Point/Polygon Attribute Table (PAT / pat.adf file).
    • Includes AREA and PERIMETER columns with the values associated with any Polygons for which the Points are labels.
    • Can be used to hold points or Polygon labels, but not both.
  • Arcs – Arc Attribute Table (ATT / att.adf file).
    • Includes FNODE#, TNODE#, LPOLY#, RPOLY#, LENGTH columns.
  • When Nodes have data associated with them - Node Attribute Table (NAT / nat.adf file).
    • Includes an ARC# column referencing one of the Arcs.
feature attribute table format
Feature Attribute Table Format
  • After the columns listed above usually come the Feature Number (NAME#) and the User Defined ID (NAME-ID) columns.
  • Following these, users can then create more columns to hold attribute data.
example pat
Example PAT
  • Note that the Universe Polygon is first, and the AREA given for it is the negative total of the rest.
other vector data
Other Vector data
  • Region – several related Polygons, nested or overlapping. Stored in a PAT.regionName (pat.adf file).
  • Annotation – text drawn along an associated feature. Stored in a T(ext)AT (txt.adf file).
  • Section – an Arc / portion of Arc representing a part of a pathway. Stored in a SEC table (sec.adf file).
  • Route – a pathway made out of multiple Sections. Stored in a R(oute)AT (rat.adf file).
putting features together
Putting features together
  • So, we’ve seen that individual features are stored in files with similar types (eg. all the line features in a file of Arcs).
  • When these are combined, you get a data “Coverage”. A Coverage usually contains one type of geographical information or analysis result, eg. “Geology”, “Roads”, or “Quickest routes”
  • Several Coverages may go together in a map, and you can turn different ones on and off to display different facets of a map.
coverages
Coverages
  • In the file system, these are represented as the directories your data files go in.
  • They let you keep data files together and display them at the same time.
  • Usually it is the name of the Coverage that goes to form the Feature Number and ID column names.
    • Eg. The SOILS coverage before gave our example PAT a SOILS# Feature Number column and a SOILS-ID column.
addition coverage information
Addition Coverage information
  • As well as our data files, a Coverage will have several other pieces of information associated with it.
    • A Coverage Extent (BND / bnd.adf file) - this records the upper right and lower left corners of a rectangle containing all the feature data in the Coverage. It need not contain all the Tic and Annotation points.
    • A Coordinate Definition file (PRJ / prj.adf ) - holds the Coverage’s map projection information
    • A Tolerances file (TOL / tol.adf ) - holds a number of processing tolerances, eg. How close Tics in different files need to be before they count as matching.
putting coverages together
Putting Coverages together
  • Finally Coverages can be kept together in project areas called “Workspaces”.
  • Workspaces allow you to keep all the data and Coverages you generate for a project in one place, separate from any other work you may be doing.
  • In the file system they’re represented as directories which include all the Coverage directories you’re working on in a project.
  • One of the first things you do on starting any ArcWorkstation project is move to your present Workspace.
the vector data model
The Vector Data Model

Filesystem

ArcCatalog

  • Different views of the same data.

Workspace

Coverages

Vector data

Raster data

TIN data

summary
Summary
  • Vector data includes Label Points, Arcs, Polygons and Tics.
  • The coordinates for the features of each type are stored in separate files, one file for each type.
  • Within the files, each individual feature has a Feature Number and a set of coordinates.
  • The Feature Number is used to link features to attribute data stored in a Feature Attribute Table of a particular type.
  • You can get at the combined data through their representation as Tables in ArcWorkstation.
summary1
Summary
  • Data stored in separate files / tables can be combined to form Coverages.
  • Coverages usually contain information about a single landuse or analysis result.
  • All the Coverages in a project can be kept together in a Workspace.
  • Coverages and Workspaces are represented as directories in the file system.
arccatalog
ArcCatalog
  • It is vital that you never alter the file names or location outside of the ArcGIS applications.
  • You can get at most of the information in the files and change/move/delete them in ArcGIS.
  • The best way to do these operations is in ArcCatalog.
  • We looked at some of the functions of ArcCatalog in the last practical. We’ll add a bit more detail now.
navigating
Navigating
  • ArcCatalog starts up displaying your harddrive, but you can add additional drives.
  • You can add online databases if they hold appropriate data.
  • Databases are a whole other course! Check ArcCatalog Help files for more details!
data viewing
Data viewing
  • Can view Coverages in a number of ways.
metadata
Metadata
  • “Data about Data”.
    • Where it’s from and what’s happened to it.
    • Who made it and what’s its problems.
    • What does it contain, and how.
  • ArcCatalog lets you see and change metadata for…
    • Describing the data and where it’s from.
    • Describing the spatial data form and projection etc.
    • Describing the attributes associated with the data.
  • Double-click on a metadata element to open up the metadata form.
  • The metadata is in the Coverage’s metadata.xml file.
  • XML is a markup language like HTML. You can open it in Internet Explorer if you want to see what it looks like.
altering and copying coverages
Altering and copying Coverages
  • You can use ArcCatalog as if it were Windows Explorer to rename, delete, copy or move Coverages and other data items, and make new folders.
  • You use exactly the same keys/menus as you would in Explorer. Most menu options can be got at by right-clicking on a folder or file.
  • The only difference is that ArcCatalog simultaneously goes through and updates all the files ArcGIS needs to keep track of what’s happened to the data.
making a workspace
Making a Workspace
  • Making a new Workspace is as easy as making a new folder.
  • File > New > ArcInfoWorkspace

(or right-click > New > ArcInfo Workspace)

  • Rename the Workspace appropriately.
  • If you look in Explorer, you’ll see an Info directory has been made in the Workspace directory to store related information.
making a coverage
Making a Coverage
  • Making a Coverage is almost as easy, but requires slightly more thought.
  • File > New > Coverage…
  • This brings up a “Wizard” (set of instructional forms to fill in) to help you.
name the coverage
Name the Coverage
  • You can use an existing coverage to supply boundary, tic and projection information.
fix the projection
Fix the projection
  • If you don’t supply a template, you’ll need to say what projection scheme it’s in, or pick none.
generate initial topology
Generate initial topology
  • If you know which feature type will be important, you can generate the appropriate feature table.
other ways of manipulating files and workspaces
Other ways of manipulating files and Workspaces
  • Command line from Arc (the web version of this lecture has equivalent notes for ArcWorkstation).
  • Using any of the

ArcTools.

  • ArcTools is a set of AML routines with menus for doing tricky Arc tasks.
summary2
Summary
  • Never alter the files or directories outside of ArcGIS.
  • The easiest way to alter, delete or move ArcGIS data is with ArcCatalog. It acts like Explorer, but informs Arc what it’s doing.
  • You can manipulate data and directories using Arc or ArcTools.
cleaning in arccatalog
Cleaning in ArcCatalog
  • Right-click on the Coverage > Properties
  • General > clean
fuzzy tolerance

X 200

Fuzzy Tolerance
  • Fuzzy Tolerance : the distance up to which points will be considered the same and snapped to the same point.
  • This helps eliminate slithers.
  • Should be small (~1/100,000 BDN rectangle size). If too small an automatic value is given (see ArcDocs).

X 200

x 1

uncleaned

cleaned

dangles
Dangles
  • Dangle Length : any overshooting Arc longer than this won’t be removed as an error.
  • Usually zero for Arc Coverages, 0.05 inches (0.127 cm) for Polygons.
  • Note that Tolerances can be set in the Coverage properties before this time (sets the TOL Table / file).

X 200

X 200

x 1

uncleaned

cleaned

building in arccatalog
Building in ArcCatalog
  • After cleaning, hit the build button to build the Topology.
  • At this point you can decide what Topology to build.
  • Just because you digitised as Polygons doesn’t mean you can’t make a set of Arcs or Nodes here for your Coverage. The Polygons will be split or Nodes extracted as appropriate.
building in arccatalog1
Building in ArcCatalog
  • Once you have your new Features (Arcs from Polygons, for example) you can go back into ArcMap and edit / delete bits using the EditorSelect tool.
editing arcedit
Editing - ArcEdit
  • By and large, not much point in using it now.
  • However, there are a few useful commands if you can seem to clean/build your topologies.
  • nodeerrors
    • Lists Arc undershoots, overshoots and open Polygons.
  • labelerrors
    • Lists where Polygons are associated with multiple labels. This should only be a problem if importing a Coverage previously produced in ArcWorkstation.
error marks
Error marks
  • Errors are marked at the Nodes where there’s a problem. Note that pseudo-Nodes (Arc crosses or Arcs join to themselves) show as diamonds. These are ok, except where they show a missing Arc i.e. two labels in one Polygon.

Overshoot

Overshoot

Undershoot

Open Polygon

Missing Arc

exporting
Exporting
  • The same ArcToolbox conversion tools let you export Coverages as different formats. Also the Arc export command.
  • Should always clean and build before exporting.
  • Supported formats include…
    • “Generate” (.gen) ASCII files.
    • Interchange “e-naught-naught” (.e00) files – a popular way of transfering ArcGIS Coverages – esp. UNIX to NT and vice versa. Includes all the information necessary.
coverage feature attribute tables
Coverage Feature Attribute Tables
  • Info stores information about each feature in a Feature Attribute Table using the Feature Number to match the attribute data to the coordinates in the geography files in a one-to-one relationship. Each data type has its own table type.

PAL

FAT

types of feature attribute table1
Types of Feature Attribute Table
  • Label Points – Point/Polygon Attribute Table (PAT / pat.adf file).
    • Includes AREA and PERIMETER columns with the values associated with any Polygons for which the Points are labels.
  • Arcs – Arc Attribute Table (ATT / att.adf file).
    • Includes FNODE#, TNODE#, LPOLY#, RPOLY#, LENGTH columns.
example pat1
Example PAT
  • Note that this Table has an extra, non-standard column in it “SOIL-CODE”.
joins
Joins
  • You can produce data tables that float free from the FATs.
  • If these have one column data in them that is…
    • Unique: i.e. is different for each record.
    • Also present in a FAT.
  • …you can JOIN the Tables, that is, copy all or some of the data out of the free-floating table and into the FAT.

New FAT

Data

FAT

tables in arcmap
Tables in ArcMap
  • Selection
  • Editing
table calculations in arcworkstation
Table Calculations in ArcWorkstation
  • In INFO use the CALC command.
  • Select Table / Records to act on.
  • Issue CALC command.
  • Results can only be numeric.
  • Can use other columns, e.g…

CALCULATE ANNUAL_WAGE = MONTHLY * 12

  • For non-numeric you need an AML or Java routine.
table relates
Table Relates
  • INFO is a relational database: one Table item can be linked to multiple items in other Tables.
  • Types of Relate
  • Relates in Coverages
  • Relation Objects in Geodatabases
table relates1
Table Relates
  • This is done without adding the data to the Table, therefore storage space lower than a Join. Also means a group of people can access one large geography file, but connect different data to it.
  • Usual to link a Feature Attribute Table (FAT) to an external data table.
  • E.g. link a country geography to Tables of population, domestic products, etc.
table joins
Table Joins
  • The relationship between items in a join must be one-to-one.
  • If not, JOIN will take the first value it comes across.

FAT

External Table

Resulting Join Table

table relates2
Table Relates
  • Relates can store one-to-many relationships and they can be used in analysis.
  • E.g. Show all SITES where at least one month has > 300mm RAINFALL and show the MONTH.
  • Again, there must be an identically named column in each, holding the data used to link the Tables.

FAT

External Table

Result

arcworkstation vs arcgis
ArcWorkstation vs. ArcGIS
  • Note: ArcWorkstation can do many-to-one, but not one-to-many. ArcDesktop can do both.

Many-to-one

One-to-many

coverage relate arc commands
Coverage Relate Arc commands
  • relate add
    • Interactively or in one go, add a relate. You can have up to 100 at a time before you have to redefine one.
  • relate drop
    • Remove a relate.
  • relate save name
    • Saves a current set of relates to a file.
  • relate restore name
    • Gets saved relates.
  • relate list
    • Lists current relates.
interfaces
Interfaces
  • ArcToolbox, ArcTools, Arc
parts of a relate
Parts of a relate
  • Relation name: arbitrary name <= 8 letters.
  • Table Identifier: name of the Table – usually not a Feature Attribute Table (FAT).
  • Database: usually INFO. Note that you don’t specify a table – the relate works on any table with the right column – usually a FAT.
  • Info Item: the column in the INFO FATs.
  • Relate column: column in the non-FAT table
  • Relate Type: how the Tables are linked.
  • Relate access: rw (read-write), ro (read only) or auto (same as the FAT).
types of relate
Types of relate
  • This is determined by the sorting in the Tables.
  • Linear: no sorting – slow unless the FAT and external table are sorted, in which case fast.
  • Ordered : related non-FAT table must be sorted by the values in the Relate column.
  • Link : relate by Feature ID. Shouldn’t be used, as the system can change IDs without warning, making the relate outdated.
  • Table: same conditions as ordered – but if an absolute match is missing the record in the related table with the next highest value is taken.
  • First: only option if you are not working with INFO.
interfaces1
Interfaces
  • ArcToolbox, ArcTools, Arc
parts of a relate1
Parts of a relate
  • Relation name: arbitrary name <= 8 letters.
  • Table Identifier: name of the Table – usually not a Feature Attribute Table (FAT).
  • Database: usually INFO. Note that you don’t specify a table – the relate works on any table with the right column – usually a FAT.
  • Info Item: the column in the INFO FATs.
  • Relate column: column in the non-FAT table
  • Relate Type: how the Tables are linked.
  • Relate access: rw (read-write), ro (read only) or auto (same as the FAT).
types of relate1
Types of relate
  • This is determined by the sorting in the Tables.
  • Linear: no sorting – slow unless the FAT and external table are sorted, in which case fast.
  • Ordered : related non-FAT table must be sorted by the values in the Relate column.
  • Link : relate by Feature ID. Shouldn’t be used, as the system can change IDs without warning, making the relate outdated.
  • Table: same conditions as ordered – but if an absolute match is missing the record in the related table with the next highest value is taken.
  • First: only option if you are not working with INFO.
arc commands
Arc Commands
  • All ArcToolbox tools have equivalent Arc commands.
  • Consult the ArcDocs command list under the tool names.
  • Most also have easy to use interfaces under ArcTool’s Command Tools.
analysis in arcworkstation
Analysis in ArcWorkstation
  • Geodatabases don’t exist.
  • Equivalent is a Network Coverage which is used in ArcPlot.
  • The Netcover command creates a Network Coverage and opens the command interface for issuing other network commands.
arcworkstation network functionality
ArcWorkstation Network functionality
  • Finding minimum-cost paths
  • Allocating supply and demand
  • Gravity modeling
  • Location-allocation modeling
  • Building a distance matrix
  • Determining connectivity
  • Assigning turn impedances
  • Ordering features
  • Classifying features
  • Listing travel directions
programming arcworkstation
Programming ArcWorkstation
  • Please see the extra materials on AML.