Topology edit tool arcgis

The default x,y tolerance is set to 0. For example, if your coordinate system is recorded in feet, the default value is 0. The default value is 10 times the default x,y resolution, and this is recommended for most cases. If coordinates are in latitude-longitude, the default x,y tolerance is 0. When a vertex of one feature in the topology is within the x,y tolerance of an edge of any other feature in the topology, the topology engine creates a new vertex on the edge to allow the features to be geometrically integrated in the clustering process.

When clustering feature vertices during topology validation, it is important to understand how the geometry of features is adjusted. All vertices of any feature class that participates in a topology can potentially be moved if they fall within the x,y tolerance of another vertex.

Vertices with higher coordinate rank features will move less and exert more gravitational pull on lower-ranked coordinates. Vertices of equal-ranked features will be geometrically averaged. It is important to note that the x,y tolerance is not intended to be used to generalize geometry shapes.

Instead, it's intended to integrate line work and boundaries during topological operations, which means to help discover features that are coincident and whose vertices are the same location.

This will integrate colocate coordinates that fall within the x,y tolerance of one another. Because coordinates can move in both x and in y by as much as the cluster tolerance, many potential problems can be resolved by processing datasets with commands that use the cluster tolerance. These include handling of extremely small overshoots or undershoots, automatic sliver removal of duplicate segments, and coordinate thinning along boundary lines.

The clustering process works by moving across the map, identifying clusters of coordinates that fall within the x,y tolerance of one another. ArcGIS uses this algorithm to discover, clean up, and manage coincident geometry between features. This means that the coordinates of the coincident geometric elements are colocated snapped to the same location.

This is fundamental to many GIS operations and concepts. As a result of the clustering process, feature vertices can potentially move more than the cluster tolerance in two ways. A topology is built on a set of feature classes that are held within a common feature dataset.

Each new topology is added to the feature dataset in which the feature classes and other data elements are held. When you create the topology, you can specify any subset of the feature classes from the feature dataset to participate in the topology according to the following conventions:.

The coordinate accuracy ranks you specify for feature classes in a geodatabase topology control the movement of feature vertices during validation.

The rank helps control how vertices are moved when they fall within the cluster tolerance of one another. Vertices within the cluster tolerance of one another are assumed to have the same location and are colocated the same coordinate values are assigned for the coordinates that fall within the cluster tolerance. When different feature classes have a different coordinate accuracy, such as when one was collected by survey or differential Global Positioning System GPS and another was digitized from a less accurate source, coordinate ranks can allow you to ensure that reliably placed vertices are the anchor locations toward which less reliable vertices are moved.

Typically, the less accurate coordinate is moved to the location of the more accurate coordinate, or a new location is computed as a weighted average distance between the coordinates in the cluster. In these cases, the weighted average distance is based on the accuracy ranks of the clustered coordinates.

The locations of equally ranked vertices are geometrically averaged when they are within the cluster tolerance of each other. Be sure to assign ranks in the proper order. The features with the highest accuracy get a rank of 1, less accurate features get a rank of 2, and so on.

Feature classes that model terrain or buildings three dimensionally have a z-value representing elevation for each vertex. Just as you control how features are snapped horizontally with x,y cluster tolerance and ranks, if a topology has feature classes that model elevation, you can control how coincident vertices are snapped vertically with the z cluster tolerance and ranks. The z cluster tolerance defines the minimum difference in elevation, or z-value, between coincident vertices.

Vertices with z-values that are within the z cluster tolerance are snapped together during the Validate Topology process. If you're modeling city buildings, two buildings may be adjacent to one another and appear to share a common edge in the x,y domain. If elevation values for building corners were collected using photogrammetry, you should be concerned about maintaining the relative height of each building structure during the topology validation process.

By setting the z cluster tolerance to a value of zero, you can prevent z-values from clustering when you validate topology. If you're modeling terrain, you may have datasets collected with different x,y and z accuracies.

In this case, you may want to set a z cluster tolerance greater than zero to allow snapping. To avoid z-values collected with a high level of accuracy snapping to z-values of lower accuracy, you can assign each feature class a rank. Lower-ranked features' z-values snap to the elevation of higher-ranked vertices if they fall within the cluster tolerance. Z-values of vertices belonging to feature classes of the same rank are averaged if they fall within the cluster tolerance.

The validate topology process averages and snaps z-values in such a way that each z-value adjusts by a total amount that is not more than the z cluster tolerance. This causes z-values of vertices with the same x,y to average or snap into groups. For example, if the z cluster tolerance is 5, z-values of these six coincident vertices average into two groups, In the following example, the coincident vertices have different ranks, and the cluster tolerance is 5.

Z-values average and snap into three groups, Z cluster tolerance values can range from zero to the extent of the z domain maximum z-value—minimum z-value. Ranks are a relative measure of accuracy. The difference in rank of two feature classes is irrelevant, so ranking them 1 and 2 is the same as ranking them 1 and 3 or 1 and Hold down A and click and drag the new vertex. Click the Delete Vertex tool on the Edit Vertices toolbar and click the vertex to delete.

You can also right-click a vertex and click Delete Vertex , or hold down the D key and click. Click the Delete Vertex tool on the Edit Vertices toolbar and drag a box around the vertices to delete. Select one or more vertices and drag and drop them to the new location. Select one or more vertices, right-click, then click Move. Right-click the vertex and click Move To.

Click and drag an arc segment, or press the R key and type a radius. Arc GIS for Desktop. Step five: Optionally, click Options to view the cluster tolerance, which is the distance that defines how close together edges and vertices must be to be considered coincident. Because ArcMap automatically determines the minimum possible cluster tolerance, you should generally use the default, because increasing the value can cause features to collapse or distort.

To get information about what you can do with topology, click the About editing topology link. This opens the related topic in the help system. That's all you need to do to set up a map to edit coincident features. If you happened to click a topology editing tool without already having a topology set up, you would be prompted to create a map topology using this dialog box.

Now that you have an active topology, edit with the tools on the Topology toolbar to make sure your features remain coincident. Use the Topology Edit tool to select edges so that you can move, modify, and reshape them.