Finding dangles on line features
Dangles occur on line features when a node at either end is not associated with the feature. This can occur if data has been corrupted or a feature has been extracted incorrectly. The Find Dangles check requires a database topology for the designated feature class. It compares the selected feature class to the others that are in the topology and searches for dangling nodes that fall within a specified tolerance of other features. The dangling nodes within this tolerance are returned as results.
The check can be run on an entire feature class, a subtype, or a set of features selected using an SQL query.
Once you have defined the criteria for the check, you can configure the notes and a severity rating. The notes allow you to provide a more specific description for the feature that has been written to the Reviewer table and are copied to the Notes field in the Reviewer table. The severity rating allows you to indicate how important the results from a check are in terms of your quality assurance/quality-control processes. The lower the number, the greater the priority the check's results have.
- Start ArcMap.
- On the main menu, click Customize > Toolbars > Data Reviewer.
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Click the Select Data Check drop-down list on the Data Reviewer toolbar, click the plus sign (+) next to Topology Checks, then click Find Dangles Check.
The Find Dangles Check Properties dialog box appears.
- If necessary, type a unique name for the check in the Check Title text box.
Remarque :
The check title can be used to describe the conditions you are looking for with the check. This is useful when you have multiple instances of the same check to validate the same feature classes or tables but with different validation parameters.
- Click the Feature Class/Subtype drop-down arrow to choose the feature class and subtype on which to run the check.
- To run the check on the entire feature class and save this setting, check the Always Run on Full Database check box.
- To run the check on specific features in a feature class, click SQL to construct an SQL query.
- Type the number of units to use as the tolerance in the Dangle Tolerance text box.
- Click the Dangle Tolerance drop-down arrow and choose the units of measurement to use with the tolerance.
- If necessary, type descriptive text for the check results in the Notes text box in the Reviewer Remarks area.
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If necessary, click the Severity drop-down arrow and choose a value that indicates the priority of the check's results in the Reviewer Remarks area.
The severity indicates the importance of the check result. The values range from 1 to 5, with 1 being the highest priority and 5 being the lowest.
- Cliquez sur OK.
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Click the Run Data Check button
on the Data Reviewer toolbar.
The Features to Validate dialog box appears.
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Choose an option in the Features to Validate area.
- Selection Set—The check is run on the features that are currently selected in the map.
- Current Extent—The check is run on the current map extent, which is controlled by the map scale.
- Definition Query—The check is run on the features that are displayed based on definition queries that have been created for the feature class.
- Full Database—The check is run on all the features in the feature class.
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To run the check only on features that have been edited in a versioned workspace, check the Changed Features Only check box.
Remarque :
The Changed Features Only option is available only for a versioned database.
- Click OK.
The check is run on the extent specified on the Features to Validate dialog box.
When the check finishes, a check results dialog box appears.
- Do one of the following:
- If you want to browse the results in the Browse Features window, choose the Browse Results option.
- If you have started a Reviewer session and want to record the results in the Reviewer table, choose the Write to Reviewer Table option.
- Cliquez sur OK.
![Attention Attention](rsrc/caution.png)
Although the Always Run on Full Database check box is available, it is not recommended to run on a feature class that is a part of a large topology dataset. Only use this option if your topology contains small amounts of data.
![Remarque Remarque](rsrc/note.png)
Running the Find Dangles check against the full database can take a long time and use extensive memory depending on the amount of data in your topology. Therefore, it is recommended that you do not choose the Full Database option, but run the check on a smaller extent by choosing one of the other options.