XY Tolerance
Release 9.2 Last modified September 4, 2007	Print all topics in : "General settings"

NOTE: In ArcGIS 9.2, the term xy tolerance has been introduced. This term is synonymous with cluster tolerance. In certain contexts the term cluster tolerance has been replaced by the term XY Tolerance.

Specify the XY Tolerance that will be used for processing and set to the output geodataset.

Learn more about XY tolerance

Usage tips

• If the output is a feature class inside a feature dataset and the XY tolerance of the feature dataset is used, the environment will be ignored.
  


• If the output is a standalone feature class, raster catalog or feature dataset, the tolerance of the input will be used as the processing tolerance and set as the output geodataset's XY tolerance. For tools that have multiple inputs (Intersect for example) the tolerance of the first input in the list will be used as the default. To override these defaults, set the XY tolerance environment to the desired value.
  


• For tools that do not have an input geodataset (for example, Create Feature Class, Create Feature Dataset, and Create Raster Catalog) and if the environment is left blank, the default XY tolerance is set to 0.001 meters or its equivalent in map units. For example, if your coordinate system is recorded in feet, the default value is 0.003281 feet (0.03937 inches). The default value is 10 * the default XY resolution, and this is recommend for most cases. If coordinates are in latitude-longitude, the default XY tolerance is 0.0000000556 degrees. To override this default, set the environment to the desired value.
  


• If the tolerance value entered for the XY tolerance environment or parameter is in a different unit than the output coordinate system, the equivalent distance measure in the center of the output coordinate system is used for processing. This may not be desirable, especially when dealing with a projected coordinate system and a angular unit of measurement (degrees, grads) or when dealing with a geographic coordinate system and a linear unit of measurement (feet, meters).
  


• If the XY tolerance is set tp "Unknown" units, the units are assumed to be the same as the output coordinate system's units.
  


• The XY tolerance is not intended to be used to generalize geometry shapes. Instead, it's intended to integrate line work and boundaries during topological operations. That means integrating coordinates that fall within very small distances of one another. Because coordinates can move in both X and Y by as much as the XY tolerance, many potential problems can be resolved by processing datasets with commands that use the XY tolerance. These include handling of extremely small overshoots or undershoots, automatic sliver removal of duplicate segments, and coordinate thinning along boundary lines.
  


• To keep movement small, keep the XY tolerance small. However, an XY tolerance that is too small (such as 2 * XY resolution or less) may not properly integrate the line work of shared boundaries.
  


• Conversely, if your XY tolerance is too large, feature coordinates may collapse on one another. This can compromise the accuracy of feature boundary representations.
  


• Your XY tolerance should never approach your data capture resolution. For example, at a map scale of 1:12,000, one inch equals 1,000 feet, and 1/50 of an inch still equals 20 feet— a data capture accuracy that would be hard to meet during digitizing and scan conversion. You'll want to keep the coordinate movement using the XY tolerance well under these numbers. Remember, the default XY Tolerance in this case would be 0.003281 feet.
  


• If the XY tolerance is not at least twice as large as the XY resolution value, the XY tolerance is set to be twice as large as the XY resolution by default.
  


• Tolerance will not be persisted to a dataset in a pre-92 geodatabase.
  
• Learn more about specifying general settings
  
• Learn more about environment settings
  
• Learn more about environment levels and hierarchy
  

Command line syntax

An overview of the command line window

XYTolerance <linear unit>

Parameters	Explanation	Datatype
<Linear unit>	The minimum distance separating all feature coordinates (nodes and vertices), and the distance a coordinate can move in X or Y (or both). You can set the value to be higher for data that has less coordinate accuracy and lower for datasets with extremely high accuracy. The default XY tolerance is set to 0.001 meters or its equivalent in map units.	Linear Unit

Data types for geoprocessing tool parameters

Command line example

XYTolerance 0.02

Scripting syntax

An overview of scripting in geoprocessing

XYTolerance (Linear unit)

Parameters	Explanation	Datatype
Linear unit (Required)	The minimum distance separating all feature coordinates (nodes and vertices) , and the distance a coordinate can move in X or Y (or both). You can set the value to be higher for data that has less coordinate accuracy and lower for datasets with extremely high accuracy. The default XY tolerance is set to 0.001 meters or its equivalent in map units.	Linear Unit

Data types for geoprocessing tool parameters

Script example

import arcgisscripting
gp = arcgisscripting.create()

gp.workspace = "H:\\Tongass"
gp.XYTolerance = "0.02"

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