4/28/2015 --- UTDallas POEC 6382 Applied GIS Software 1 Editing Coverages in ArcEdit

04/18/23 --- UTDallas POEC 6382 Applied GIS Software1

Editing Coverages in ArcEdit


The Six Basic ARCEDIT Steps1. Set display environment and coordinate input2. Specify edit coverage and edit feature3. Set drawing environment for edit and back

coverages4. Set snap environment and edit tolerances5. Add new features or edit positional information of

coverage features 6. SAVING changes, undoing changes, and exiting

ARCEDIT

Put steps 1 - 4 in AML; 5 & 6 perform at prompt


Step 1 - Set Display Environment & Coordinate Input

DISPLAY ENVIRONMENT

• ARCEDIT: display 9999

• ARCEDIT: &term 9999

COORDINATE INPUT - specify the mode of interactive coordinate entry for ARCEDIT commands that require coordinate input. You can change this multiple times per session. Default is cursor; do not need to change for heads-up digitizing.

• ARCEDIT: coordinate < CURSOR | TABLET | MOUSE>

• ARCEDIT: coordinate keyboard

• ARCEDIT: coordinate digitizer


Step 2 - Specify edit coverage and edit feature

• Specify which coverage and which type of feature to be edited. These are called the edit coverage and edit feature.

• During an ARCEDIT session you can change both frequently.

• You can have up to ten edit coverages within an ARCEDIT session

• The most recently specified edit coverages is the active one.

• Editfeature can be abbreviated to EF

ARCEDIT: edit <cover>

ARCEDIT: editfeature <feature_class>


Step 3. Set drawing environment for edit and back coverages

• A back coverage is for display only; they are not edited, but may assist in editing another coverage. Designate a back coverage with the backcover command.*

ARCEDIT: backcover <cover> {symbol}

• An image can also be utilized as a background to the edit coverage; simply call the image *

ARCEDIT: image 75069876.jpg

• The backenvironment command specifies which feature classes will be drawn for the back coverage.

ARCEDIT: backe arc polygon

*Note: nothing will draw in your graphics window until the DRAW command is given


Step 3. Set drawing environment for edit and back coverages, (page 2)

• The drawenvironment command specifies which feature classes will be drawn for the edit coverage. – The default setting assumes that no features will be drawn. You

must specify each feature type to be drawn.

– Each feature class can be drawn in a variety of ways -- see the on-line help for the drawenvironment command to review the options. The default for each feature class specified in the command line is ON, therefore it is not necessary to choose that option.

• If editing arcs, it is a good idea to draw nodes with errors (dangling and pseudo) drawn with their special symbols (box for dangling, diamond for pseudo). The drawing environment will automatically update the symbols as errors are corrected or introduced.

ARCEDIT: drawe arc node errors


Step 3. Set draw symbols for pseudo and dangling nodes (page 3)

• NODECOLOR allows you to specify a color with which nodes are drawn when the edit coverage does not have a node attribute table.

• NODECOLOR <NODE | DANGLE | PSEUDO> <color>

– Arcedit: nodecolor dangle 2

– Arcedit: nodecolor pseudo 3


Step 3 Draw features (page 4)

• Set the map extent

ARCEDIT: mape {* | DEFAULT | SELECT}

ARCEDIT: mape <backcover>

ARCEDIT: mape <xmin ymin xmax ymax>

ARCEDIT: mape IMAGE <image>The DEFAULT argument sets the map extent to the edit coverage’s

stored map extent. The SELECT argument will set the mape extent to span exactly the selected features in the edit coverage and edit feature.

• Draw features specified up to this point (edit cover, backcover, image, if specified).

ARCEDIT: draw


Step 4. Set snap environment and edit tolerances

• The snap environment positions new or modified features to exactly match the positions of other features.

• There are three types of snapping:

– node snapping

– arc snapping

– general snapping

• Will not snap features already digitized; it affects newly added or edited features only.


NODE SNAPPING (step 4, p.2)

A new node is snapped to an existing node if it is within the node snapping distance.

ARCEDIT: nodesnap <FIRST | CLOSEST | OFF> {DEFAULT | * | distance}

Specifies whether the FIRST node found within the distance is snapped to, or the CLOSEST node. OFF turns nodesnapping off.


ARC SNAPPING (Step 4, p. 3)

Arc snapping helps you snap new arcs to existing arcs. Arc snapping is used to correct undershoots and overshoots.

ARCEDIT: arcsnap on {* | distance}

ARCEDIT: arcsnap off


GENERAL SNAPPING (Step 4, p. 4)• General snapping ensures that features which should align

precisely to others are snapped.– Example -- set the addition of point features which represent

transformers in an electrical utility coverage to lie exactly upon an electrical line.

• All new digitized or modified features can be snapped:

Snapcoverage specifies the coverage containing the features to snap to; snapfeatures specifies which type of feature in the edit coverage should be snapped to which type of feature in the snap coverage.

ARCEDIT: snapcoverage <cover>

ARCEDIT: snapfeatures <feature_type><feature_type>

ARCEDIT: snapping <OFF | FIRST | CLOSEST>

{* | DEFAULT | distance}


EDIT TOLERANCE (Step 4, p. 5)• EDITDISTANCE specifies how close the screen cursor

must be to a target feature to successfully select it.

ARCEDIT: editdistance {* | DEFAULT| distance }• GRAIN tolerance and WEEDTOLERANCE set the

closest distance between adjacent arc vertices. – GRAIN tolerance is used for modifying existing arcs with

ARCEDIT comands such as SPLINE and for adding curved arcs with ADD.

ARCEDIT: grain {* | DEFAULT| distance }– WEEDTOLERANCE is used for new arcs you digitize with the

ARCEDIT ADD command and when modifying selected arcs with GENERALIZE.

ARCEDIT: weedtolerance {* | DEFAULT| distance }


Set the Draw Symbol (Step 4, p. 6)

• SETDRAWSYMBOL specifies a symbol and color for highlighting features as they are selected.

SETDRAWSYMBOL <symbol> {color}

<symbol> - the number of a symbol in the current symbolset. <symbol> must be an integer between 1 and 999. Enter a 0 for the symbol if you want to change only the color of features as they are redrawn.

{color} - the color with which selected features will be drawn. Yellow is the default highlight color when ARCEDIT starts.


Step 5. Add new features or edit positional information of coverage features

• ARCEDIT commands:

– add

– select

– move

– copy

– oops

– align

– densify

– drag

– extend

– flip

– generalize

– reshape

– rotate

– spline

– split

– unsplit

– vertex add

– vertex draw

– vertex delete

– vertex move

– merge

– annoplace


Adding and Editing ARCS and NODES (step 5 contd)

• The arc is the fundamental feature type in Arc/INFO (remember, polygons are stored as a list of arcs). There are more Arcedit commands to edit arcs and their nodes and vertices than for any other feature type.

• Nodes cannot exist without arcs. Many commands that modify arcs will also affect the placement or creation of nodes.

• To add or modify arcs, first set the edit feature to arc, and the drawenvironment for arcs and nodes.

• See your text, page 375, for a list of useful drawenvironment settings.


• Node types

• Identifying node types can be important for coverage automation. There are three types: normal, pseudo and dangling. Dangling and pseudo nodes often identify automation errors; however, they can also be valid components of a feature.



(Step 5, page 4)





• INTERSECTARCS - this command determines whether or not intersections are created when you add, move or change coordinates of arcs. Default is OFF. Use the add or all setting if you will need polygon topology.– Arcedit: intersectarcs <off | add | all>



• ADD The ADD command brings up menus designed for each type of edit feature. The current edit feature determines the class of feature to be added, for example, you cannot add arcs if the current edit feature is label.

• Arcs can be digitized as straight segments (lines), boxes, circles or as the center line between specified points. To change the type of arc, you can use the ARCTYPE command

Arcedit: arctype < line | box | circle | centerline >

Most of the time you will use the default, which is line



• Issue ADD and the following Options menu will display with a User-ID prompt for the arc to be added.Arcedit: ADD

------------------------------- Options ---------------------------------------

1) Vertex 2) Node 3) Curve

4) Delete vertex 5) Delete arc 6) Spline on/off

7) Square on/off 8) Digitizing Options 9) Quit

– Move the cursor to the point you want to start drawing in the graphics screen then choose an option key on your keyboard (1 to 9).

– Arcs always begin with a node (2) and end with a node. Stop adding with quit (9). Your cursor must stay in the graphics window when entering options.

– Changes along the line are marked by vertices (1).

– See your textbook, page 378 for digitizing steps, and look at ArcDoc on ADD for diagrams.



• SELECT - selects features to edit.

SELECT {ONE | MANY | ALL | OUTLINE | DANGLE | CONNECT | UNCLOSED}

ONE - specifies that a single feature will become the currently selected set. This is the default option for SELECT.

• After entering SELECT at the ArcEdit prompt, you will be prompted to position the cursor at the location of the feature you wish to select and press the 1 key. The feature selected will be drawn in yellow or in the current symbol specified with SETDRAWSYMBOL.



• COPY - will copy the arcs that are in your selected set.

• Copying coverage features prompts you to enter the from and to coordinates. These points can be entered anywhere on the coverage.

• COPY duplicates all attributes of selected elements, including the coverage ID of features.

• COPY MANY can be used to copy the same feature(s) as many times as needed.

• COPY PARALLEL { * | distance } will copy the single arc you have selected to a parallel offset as shown in the illustration.



• MOVE - moves the currently selected features to a new user-specified location.

• MOVE {PARALLEL {* | distance}}

• MOVE, without any arguments, prompts you to enter a from-coordinate and to-coordinate, and then moves the selected features the relative distance and direction between the two points.

• {PARALLEL} - specifies that selected arcs will be moved parallel to themselves. This option is only available for the edit feature arc.

• {* | distance} - specifies the distance the selected arc(s) will be moved parallel from itself.



• DELETE removes the selected arcs from your coverage.

• If you accidentally deleted arcs, use the OOPS command to restore them. You cannot restore deleted arcs after a SAVE.

• OOPS undoes the most recent transaction to the features of the current edit coverage. A transaction is any change that alters the coverage, such as ADD, COPY, CALCULATE, and MOVE. You can undo transactions all the way back to where the current edit coverage was specified with the EDIT command or back to the last save. Commands like DRAW, CLEAR, and EDITDISTANCE, which set the environment, cannot be undone.



Adding and Editing VERTICES (step 5 contd)

• The VERTEX command performs many edit operations on vertices.

• Before you use this comand , you should select only one arc. Otherwise, it may take hours to draw all the vertices in one coverage.

• VERTEX DRAW displays all vertices in the selected arc as snall, solid-filled cirecles.

• VERTEX ADD lets you add vertices to the selectred arc

• VERTEX DELETE lets you remove vertices from the selected arc.

• VERTEX MOVE lets you move vertices from the selected arc.


Step 6. SAVING changes, undoing changes, and exiting ARCEDIT

• During an ARCEDIT session you are working on temporary files when you add, modify, or delete features. The actual coverage is not updated until you SAVE the changes.

• The OOPS command lets you undo the mose recent edit, and to step back through your edits to remove as many edits as needed. This is not possible if you have already SAVED your edits.

• SAVE is usually used without arguments. Use often if there is the chance of power failures or other reason you might lose your edits, but be sure your edits are correct prior to saving.

• Use QUIT to exit Arcedit.


Summary of Your ArcEdit Session - page 1Step 1 - SET DISPLAY ENVIRONMENT• ARCEDIT: display 9999• ARCEDIT: &term 9999• ARCEDIT: mape <cover>Step 2 - Specify edit coverage and edit feature• ARCEDIT: edit <cover>• ARCEDIT: editfeature <feature_class>Step 3 - Set drawing environment for edit and back

coverages• ARCEDIT: image <name>.jpg• ARCEDIT: backcover <cover> {symbol}• ARCEDIT: backe <feature_class>• ARCEDIT: drawe arc poly node errors


Summary of Your ArcEdit Session - page 2• Step 4 - Set snap environment and edit tolerances (and

drawing features)• ARCEDIT: mapunits feet• ARCEDIT: mapscale automatic• ARCEDIT: nodesnap closest 20• ARCEDIT: arcsnap on 20• ARCEDIT: editdistance 20• ARCEDIT: intersectarcs all• ARCEDIT: setdrawsymbol 1 cyan• ARCEDIT: nodecolor dangle 2• ARCEDIT: nodecolor pseudo 3• ARCEDIT: draw


Coverage Creation

• Coverages can be generated using an ascii file with x,y coordinates, or they can be created using registration TICS and a boundary file from an existing coverage or by inputting Tic-IDs and locations for at least four tics in ArcEdit.

• Creation of a coverage using registration TICS (tic.adf) and a boundary file (bnd.adf) from an existing coverage or tics that you enter in ArcEdit results in an “empty” (no feature class present) coverage. During coverage creation, the projection file (prj.adf) will also be copied from the existing coverage to the new coverage, if one was present.

• The command CREATE can be used at either the Arc prompt or the ArcEdit prompt.


Creating Feature Attribute Table• Feature Attribute Tables are created in Arc when topology

is “built”. • To create a feature attribute table for a coverage created in

ArcEdit you have several options:– Save your edits, exit Arcedit, build topology at the Arc

prompt - this is the fail-proof method.– For polygon topology, use the BUILD command at the

ArcEdit prompt. Labels with unique IDs are added at the centroid.

– For point or arc topology, use CREATEATTRIBUTES command

• OOPS will undo build or createattributes in ArcEdit unless edits have been saved.


Using ArcEdit to add values to an item in the Feature Attribute Table

• FORMS opens a form menu for editing attributes.

• A feature attribute table must exist for the features to be edited and additional items added with ADDITEM.

• You must SAVE the new attribute items before starting FORMS because FORMS reads the items from INFO, not from ARCEDIT’s temporary files.

• FORMS works on the current edit feature.

• FORMS works on the selected set of elements. If no elements are selected when FORMS is executed, all features or INFO records will be selected.


Annotation

• Annotation is a unique coverage feature class that stores labels used to describe other geographic features.

• Annotation can be organized into annotation subclasses and levels. For example, a coverage storing roads may have street names in one annotation level, highway names in another level, and place names in a third level. Alternatively, the roads coverage might have two subclasses, one for street names and one for highway names, each containing several levels for specific annotation text sizes.


Annotation, page 2

• ANNOTEXT draws annotation using the text symbol numbers stored with the annotation. The symbol numbers access text symbol definitions from the currently loaded textset file. If a textset file was specified with the TEXTSET command when the annotation was created (either in ARCPLOT or ARCEDIT), the same set should be loaded with the TEXTSET command before using ANNOTEXT to draw the annotation. In this way the correct text symbols will be used to draw the annotation.


Using an item value to create annotation

• Step 1 - Create an annotation attribute table (.TAT)– Arcedit: createfeature anno.bldg

• Step 2 - Specify the edit feature– Arcedit: editfeature anno.bldg

• Step 3 - Specify the drawing and symbolization environmts– Arcedit: textset font.txt (also look at annosymbol, annoplace,

annooffset, annoalignment, annoposition, annosize)

• Step 4 - Specify the feature on which to place annotation and the source of the annotation (item name).– Arcedit: annofeature poly name

• Step 5 - Capture annotation based on the current setting of the ANNOFEATURE command.– Arcedit: annocapture


Editing Feature Attributes

• Editing feature attributes in ArcEdit utilizes the same commands as in Arcplot, CALCULATE and MOVEITEM, and the commands have the same functionality as in ArcPlot or in INFO.

• Both commands operate upon the current edit feature and selected set.

• CALCULATE <target_item> = <arithmetic_expression>

• MOVEITEM <‘character_string’ | source_item> {TO} <target_item>


Transferring features between coverages

• The PUT and GET commands are designed to transfer features between coverages.

• The PUT command takes the features in your edit coverage, edit feature, and selected set, and writes them out to the specified coverage. If the coverage specified does not yet exist, this command will create a new coverage. Otherwise the new features will be appended to the existing features. WARNING: You can not undo the PUT command.

• The GET command imports all the features from the specified coverage. Any snapping environment or edit tolerances currently set are applied on the imported features.

Documents

4/28/2015 --- UTDallas POEC 6382 Applied GIS Software 1 Editing Coverages in ArcEdit