ArcGIS for Desktop Cookbook
上QQ阅读APP看书，第一时间看更新
上一章目录下一章

Editing features in a geodatabase

In ArcMap, a layer references the spatial datasets (for example, feature class and raster) that contain features with common geometry and attributes. A layer uses the dataset attributes to represent the features by one or more symbols. By default, a layer symbolizes features from a feature class using the subtype field.

The editing session in ArcGIS for Desktop is based on layers. When you start an edit session, you have to define the Feature Template that describes the type of feature that you intend to create. ArcGIS creates feature templates by default, based on the layer symbology. In the Creating Feature window, you can see the list of feature templates. You can create new types of features with the Organize Feature Templates option. Moreover, you can define a default attribute for one type of feature or for all types of features from a layer. When you create a new feature, the default attribute is automatically inherited. Choosing a default value works for subtypes and domains, too.

After you create a feature, you should edit its attributes using the Attribute window. Most of the attribute fields will automatically get completed according to the default subtype and domains you already defined in the Using subtypes and domains together recipe of Chapter 1, Designing Geodatabase.

Getting ready

In Chapter 1, Designing Geodatabase, you learned how to create the Topo5k.gdb file geodatabase schema. Now, it's time to add data. There are several ways to add data into a geodatabase:

  • Using the Import/Export and Load Data options in ArcCatalog
  • Using the Load Objects option in an ArcMap environment
  • Creating new features by screen digitizing and by editing existing ones
  • Using the Export Data option in an ArcMap environment

In this recipe, you will work with the Editor, Snapping, and Edit Vertices toolbars to create new features and to edit the existing features. The LandUse and BuildingsR feature classes already contain features. The features were digitized based on a scanned topographic map at scale 1:5,000 produced in 1995.

As a base layer for updating features, you will use an orthophotography from 2012 corresponding to a map at scale 1:5,000. The orthophoto map has a resolution of 1 pixel =0.5 meter and is stored as Raster Dataset in the Topo5k.gdb geodatabase.

Even if you assume that you are already comfortable with the elementary edit process in ArcGIS 10, please remember the main steps:

  1. Start the edit session.
  2. Set the snap environment (optional).
  3. Before starting a sketch, choose a feature template and a construction tool.
  4. Create the new feature.
  5. Add or modify attribute values of the feature.
  6. Save edits.
  7. Stop the edit session.

How to do it...

You can follow these steps to edit features in a geodatabase:

  1. Start ArcMap, and open an existing map document Editing.mxd from <drive>:\PacktPublishing\Data\EditingData. Notice that layers from the Table Of Contents section are symbolized based on their subtypes. The LandUse layer has defined a transparency. Right-click on the LandUse layer, and navigate to Properties | Display. You will notice that Transparent has a 60 percent value. Let's add a pop-up label with the OBJECTID value in the data view. Check Show MapTips using the display expression, and choose the desired field. Click on OK.
  2. From the Bookmarks menu, select Create a Fish Pond. You will create a new feature in the LandUse layer, as shown in the following screenshot:
    How to do it...
  3. In the Table Of Contents section, right-click on the LandUse layer, and navigate to Edit Features | Start Editing. In the Editor toolbar, navigate to Editor | Editing Windows. In the Create Feature window, you will see the feature templates for all layers that are visible in the Table Of Contents section.
  4. In the Editor toolbar, navigate to Editor | Snapping, and check the Snapping toolbar. In the Snapping toolbar, select only Vertex Snapping. Snapping options assure the coincidence of new feature coordinates with the coordinates of existing features.
  5. In the Editor toolbar, navigate to Editor | Options | Attributes. Navigate to Display the attributes dialog before storing new features | For the following layers options | LandUse. Click on OK. Every time you create a new LandUse feature, the Attribute window will show up after you have finished the sketch.
  6. Select the feature with OBJECTID as 755 from the LandUse layer. In the Editor toolbar, select the Cut Polygons Tool option to cut the arable polygon.
  7. Select the Trace tool. Right-click on the polygon, and select Trace Options. In the Trace Options dialog, type 5 as the Offset value, select the Trace selected features option, and click on OK.
  8. Use the screenshot from step 2 to follow the edit steps. Start the sketch from point (1) and finish it at point (2). Right-click on point (2) to choose a value for the Length field, type in 84, and close the window. Move the segment towards point (3), and add the end of the curve to point (4).

    Tip

    While you are sketching, press Tab to display the Feature Construction toolbar.

  9. Again, go to point (2), and right-click on it to choose a value for the Length field, type in 61, and close the window. Move the segment to point (5), and add the last vertex to point (6). To finish the sketch, use the F2 shortcut key.

    Next, you will edit the attribute fields for the new polygon feature, as shown in the following screenshot:

    How to do it...
  10. In the Attributes window that automatically opens, select the new LandUse feature you just created. The default value for Category (CAT) and SubCategory (SCAT) is Arable. You defined the default values in the Using subtypes and domains together recipe of Chapter 1, Designing Geodatabase.
  11. Let's change the attribute values. Select the Category field, and click on the small button from the right to open the Choose Symbol Class window. Select the Hydrography value, and click on OK. For the SubCategory field, select the Fish pond value from the drop-down list. For LandUseID, type the value of OBJECTID. Click on OK to close the window.
  12. Return to the Attribute window, and expand the nodes for the Fish Pond feature to see the relationships. The new LandUse feature is related to the BuildingsR layer (BuildingsR-ToBuildingsR) and Owners table (Owners-ToOwners). Select the Owners-ToOwners relationship to define the owners of the parcel.
  13. Right-click and navigate to Table | Open Attribute Table. In the Owners table, select the owner with NameOwners as Owner1. At this point, open the attribute tables for the LandUse and BuildingsR feature classes and for the LandUseToOwners relationship. To see LandUseToOwners and BuildingsRToOwners relationship tables and the Owners nonspatial table, click on the List By Source button in the Table Of Contents section.

    Tip

    To see the tables as shown in the preceding screenshot, click on the tab of the LandUse table and drag it within the Table window. When you see the Dock icon, drag the selected table to the right or down docked position.

  14. Return to the Attribute window, and right-click on the LandUse feature relationship: Owners-ToOwners. Select Add Selected. Now, your parcel has an owner with OBJECTID as 1.

    You should check the relationship class table named LandUseToOwners; it stores the relationship between Fish Pond and Owner1.

  15. In the Table window, select the LandUseToOwners table to check the changes. Edit the OwnerProcent attribute field with its value as 100. Select and inspect the Owners table. To see how many parcels and buildings own the Owner1 table, click on the Related Tables button, and choose the two relationships one by one: LandUseToOwners:ToLandUse and BuildingsRToOwners:ToBuildingsR.

    Next, you will create a new parcel and modify two vertices of a dwelling. In the following screenshot, you have all elements to create a new parcel by splitting the arable polygon:

    How to do it...
  16. Click on Bookmarks, and select Cut a Parcel and modify a Building.
  17. Select the parcel with OBJECTID as 755 from the LandUse layer.
  18. First, go to the Snapping toolbox and keep only the Vertex Snapping option selected.
  19. Second, select the Cut Polygons Tool option. Start the sketch from point (1) and select the Distance-Distance tool. Click on point (1) as a center for the first circle, and press the D key to type 77 for Distance. Click on point (2) as a second center, and press the D key to type 139 for Distance. You have obtained a point as an intersection of two circles. Click on the first intersection to obtain the second vertex of the cutting polyline.
  20. Again, select the Distance-Distance tool. Click on point (2) as a center for the first circle, and press the D key to type 128 for Distance. Click on point (3) as a second center, and press the D key to type 135 for Distance. Click on the second intersection to obtain the third vertex of the cutting polyline.
  21. Select Straight Segment, and click on point (2). To finish the cutting sketch, press the F2 shortcut key.
  22. In the Attributes window, select the following values: Category as Other terrains, SubCategory as Built-up area, and for LandUseID, type the value of OBJECTID. Click on OK.
  23. The new LandUse feature is related with the BuildingsR layer (BuildingsR-ToBuildingsR) and the Owners table (Owners-ToOwners). Try to manage those relationships by yourself. How to start? Firstly, with Shift pressed, select the building with the Select Features tool. Secondly, select BuildingsR-ToBuildingsR, and right-click on it to choose the Add Selected option.

    Next, you will correct the position of two vertices of the building according to the orthophoto map used as a background:

  24. Keep the building selected and with the Shift key pressed, unselect the parcel. Click on Edit Vertices, and from the toolbar, choose Modify Sketch Vertices. Select the two vertices by drawing a small box around the vertices. Drag the selected segment, and drop it as shown in the preceding screenshot.

    Finally, you will correct a neighboring LandUse parcel. You have two options, as shown in the following screenshot:

    How to do it...
  25. Use the Reshape Feature Tool option to draw a line as point (1) from the preceding screenshot in order to cut the polygon with OBJECTID as 755 from the LandUse layer. You have created a gap between the parcels. To modify the parcel from the left-hand side, select the Other Terrains option with the Auto Complete Polygon construction tool from the Create Feature window. Put the first vertex in the gap and the second in the neighboring parcel—see point (2). With the Select Features tool, select both the parcels, and from the Editor toolbar, select Merge. In the Merge dialog, select Build-up area (LandUse), and click on OK.
  26. Use the Cut Polygons Tool option to split the polygon. With the Select Features tool, select the two parcels from point (3). From the Editor toolbar, select Merge. In the Merge dialog, select Build-up area (LandUse), and click on OK.
  27. In the Editor toolbar, navigate to Editor | Stop Editing, and save your edit. Navigate to File | Save As, and save your map as MyEditing.mxd.

You can find the final results at <drive>:\PacktPublishing\Data\EditingData\ MyEditingResults\Editing.mxd.

How it works...

To select an existing parcel from the LandUse layer, and in order to edit it, first use the Select Features tool, and after that, select the specific edit tools from the Editor toolbar. If you use an Edit tool to select a feature, there is always a risk that you will create a subtle movement of the selected feature. A small shift will create overlaps and gaps between the coincident features. To protect features from this small shift, navigate to Editor | Options | General | Sticky move tolerance, and set a minimum distance for cursor movement before the selected feature will be moved too.

At step 23, we tested the multiple vertex editing. We have selected two vertices and moved them at once.

Tip

You can change the geometry of a segment by selecting two vertices.

Right-click on the segment, select Change Segment, and choose one of the options: Bezier or Circular Arc.

You can also delete multiple vertices at the same time.

In the Creating a relationship class recipe of Chapter 1, Designing Geodatabase, we created relationship rules between the LandUse, BuildingsR, and Owners tables. We have already noticed at step 12 that relationships are active and must be updated every time we add new features. The relationship rules can be validated during the edit session. Select all features from BuildingsR and LandUse using the Select Features tool. In the Editor toolbar, navigate to Editor | Validate Features. A message box will appear stating 72 features are invalid. Click on OK to close. All invalid features are selected. In the Attributes window, inspect and try to correct the errors yourself.

There's more...

To add more data to your geodatabase schema, we will test two more options: Load Data using ArcCatalog and Load Objects in the ArcMap environment. Follow these steps to add the data in the geodatabase file using Load data:

  1. Start ArcMap, and open the existing Editing.mxd map document from <drive>:\PacktPublishing\Data\EditingData.
  2. Open the Catalog window from the Standard toolbar to have access to your data. In the Catalog window, right-click on WatercourseL from ...\EditingData\Topo5k.gdb, and navigate to Load | Load Data. Set the following parameters from panels:
    • The Input data parameter as the ...\Data\TOPO5000.gdb\Hydrography\ WatercourseL feature class; click on Add
    • Check I do not want to load all features into a subtype
    • Target Field (destination) and Matching Source Field (source): 
      HYC[int] = HIC[int]
Name[string] = Name[string]
HType[int] = HAT[int]
    • Check Load all of the source data
  3. Click on Next and Finish. In the Table Of Contents section, right-click on WatercourseL, and choose Zoom To Layer to see the polyline features.

    Continue to follow the steps to populate the Watercourse feature class with features from the LandUse feature class using Load Objects in ArcMap.

  4. To add the Load Objects tool, click on the drop-down arrow from the right-hand side of the Editor toolbar, and select Customize. Select Commands, and for Show commands containing, type load objects. From Commands, click and drag the Load Objects option to the Editor toolbar. Click on Close. To use this tool, you need to start the editing session.
  5. Before starting an edit session, in the Table Of Contents section, right-click on Watercourse, and navigate to Edit Features | Organize Feature Templates. You will define a default value for the Name field. All the new features from Watercourse that you add in this edit session will have the Name field as River Flake. In the Organize Feature Templates window, select Watercourse from the Layers section. With the Ctrl key pressed, select the River and Stream templates. Click on Properties, and for Water Name, type River Flake. Click on OK and then on Close.
  6. Start the edit session from the Editor toolbar by navigating to Editor | Start Editing.
  7. In the Table Of Contents section, right-click on Watercourse, and select Load Objects. Set the following parameters from panels:
    • The Input Data parameter as the ...\Data\EditingData\Topo5k.gdb\LandUse\LandUse feature class; click on Add
    • The Target field as the Stream subtype
    • Accept the default matching Target Field (destination) and Matching Source (source)
    • Check Load only the features that satisfy a query
    • Click on Query Builder and build the following expression:

      CAT=31

    • Accept all the other default parameters
  8. Click on Finish. In the Table Of Contents section, right-click on Watercourse, and choose Zoom To Layer.
  9. Select all vectors using the Select Features tool from the Tools toolbar and open the Attributes window. All nine Stream features have the same attribute value for the HYC field as Intermittent. This is because in the Using subtypes and domains together recipe of Chapter 1, Designing Geodatabase, we have assigned the domain code 2 (Intermittent) as the default value of the HYC field for the Stream subtype features.

Let's suppose that we mistakenly chose to load all objects in the Stream subtype. To change the subtype value to River for all the nine features at the same time, select the Watercourse layer in the Attributes window. Click on the icon from the left Stream value to open the Choose Symbol Class window. Select the River value, and click on OK. Read carefully the warning message, and select Yes to automatically assign the corresponding Perennial default values for HYC. The Name field already has the River Flake value. Notice that every feature has the same HType and HYC and the Name value. In the Editor toolbar, navigate to Editor | Stop Editing, and save your edit. Navigate to File | Save As, and save your map as Editing.mxd. You can find the final results in <drive>:\PacktPublishing\Data\EditingData\ MyEditingResults\Topo5k.gdb.

Recall that you constrained the attribute values by subtypes and domains in Chapter 1, Designing Geodatabase. Every time you load features from other sources, such as existing feature classes or shapefiles, don't forget to validate the attribute values during the edit session. The Validate Features option will identify all the invalid values for the attribute fields for which you have already defined the subtypes and domains. All features that have invalid values will be selected. You should inspect and correct the reported errors with the Attributes window.

See also

  • In the next recipe, Advanced editing in a geodatabase, you will continue to work with advanced editing tools and with COordinate GeOmetry (COGO)
上一章目录下一章