Summary
Calculates distances and other proximity information between features in one or more feature classes or layers. Unlike the Near tool, which modifies the input, Generate Near Table writes results to a new stand-alone table and supports finding more than one near feature.
Learn more about how proximity is calculated by geoprocessing tools
Illustration
Usage
The output table will contain the following fields:
- IN_FID—The ObjectID of the input feature.
- NEAR_FID—The ObjectID of the nearest feature.
- NEAR_DIST—The distance from the input feature to the near feature. The value distance unit of this field is the linear unit of the input feature's coordinate system, or meters when the Method parameter is set to Geodesic and the input is in a geographic coordinate system.
- NEAR_FC—The catalog path to the feature class that contains the near feature. This field is only added to the output table if multiple Near Features values are specified.
- NEAR_RANK—An integer value ranking all near features based on their proximity to an individual input feature. The closest feature will have a value of 1, the second closest will have a value of 2, and so on.
The following fields will be added to the output table if the Location parameter is checked (location parameter set to LOCATION in Python). The unit of the values of the fields depends on which method is used for the Method parameter. If Planar is used, the value unit is the linear unit of the input feature's coordinate system. If Geodesic is used, the value unit is the geographic coordinate system associated with the input feature's coordinate system.
- FROM_X—The x-coordinate of the location on the input feature that is closest to the near feature
- FROM_Y—The y-coordinate of the location on the input feature that is closest to the near feature
- NEAR_X—The x-coordinate of the location on the near feature that is closest to the input feature
- NEAR_Y—The y-coordinate of the location on the near feature that is closest to the input feature
The following field will be added to the output table if the Angle parameter is checked (angle parameter set to ANGLE in Python).
- NEAR_ANGLE—The angle of the line at the FROM_X and FROM_Y location that connects the input features to the near feature
When the input and near feature intersect, the following values will be written to the output table:
- NEAR_ANGLE and NEAR_DIST will be set to 0.0.
- FROM_X and FROM_Y will be identical to NEAR_X and NEAR_Y and will be a location within the intersection of the two features.
The values in the NEAR_DIST field will be in the linear unit of the input features coordinate system. If the input is in a geographic coordinate system and the Method parameter is set to Geodesic, the units of the NEAR_DIST field will be meters.
The output table can be joined back to the input features using the IN_FID field or to the near features using the NEAR_FID field.
If the Search Radius parameter is specified and no near feature is found, no record will be output.
If the Search Radius parameter is not specified, all near features will be considered candidates.
If the Search Radius parameter is not specified, the Find only closest features parameter is unchecked, and the Maximum number of closest matches parameter is set to the default (0 or empty), the output table will contain distance calculations between all input features and all near features. This process can take a long time and can create a large output table. For example, if you have 1,000 input features and 1,000 near features, the output table will contain 1,000,000 records.
The same feature class or layer can be used as both input and near features. In this situation, the input feature being evaluated will be excluded from the near features candidates to avoid all features being closest to themselves.
When using the Planar option for the Method parameter, use a projection for the input features that is appropriate for distance measurement, such as an equidistant projections.
Learn more about geographic and projected coordinate systems
To visualize the FROM_X, FROM_Y, NEAR_X, and NEAR_Y field values, the output table can be used as input to the Make XY Event Layeror XY To Line tool.
Syntax
arcpy.analysis.GenerateNearTable(in_features, near_features, out_table, {search_radius}, {location}, {angle}, {closest}, {closest_count}, {method})| Parameter | Explanation | Data Type |
in_features | The input features that can be point, polyline, polygon, or multipoint type. | Feature Layer |
near_features [near_features,...] | One or more layers of a feature class containing near feature candidates. The near features can be point, polyline, polygon, or multipoint. If multiple layers or feature classes are specified, a NEAR_FC field will be added to the input table and will store the paths of the source feature class containing the nearest feature found. The same feature class or layer can be used as both input and near features. | Feature Layer |
out_table |
The output table containing the result of the analysis. | Table |
search_radius (Optional) | The radius that will be used to search for near features. If no value is specified, all near features will be candidates. If a distance is entered, but the unit is left blank or set to Unknown, the units of the coordinate system of the input features will be used. If the GEODESIC option is used for the method parameter, use a linear unit such as kilometers or miles. | Linear Unit |
location (Optional) | Specifies whether x- and y-coordinates of the input feature's location and nearest location of the near feature will be written to the FROM_X, FROM_Y, NEAR_X, and NEAR_Y fields.
| Boolean |
angle (Optional) | Specifies whether the near angle will be calculated and written to the NEAR_ANGLE field in the output table. A near angle measures direction of the line connecting an input feature to its nearest feature at their closest locations. When the PLANAR method is used for the method parameter, the angle is within the range of -180° to 180°, with 0° to the east, 90° to the north, 180° (or -180°) to the west, and -90° to the south. When the GEODESIC method is used for the method parameter, the angle is within the range of -180° to 180°, with 0° to the north, 90° to the east, 180° (or -180°) to the south, and -90° to the west.
| Boolean |
closest (Optional) | Specifies whether only the closest feature will be written to the output table.
| Boolean |
closest_count (Optional) | Limits the number of near features reported for each input feature. This parameter is ignored if the closest parameter is set to CLOSEST. | Long |
method (Optional) | Specifies whether a shortest path on a spheroid (geodesic) or a flat earth (planar) distance method will be used. It is recommended that you use the GEODESIC method for data stored in a coordinate system that is not appropriate for distance measurements (for example, Web Mercator and any geographic coordinate system) and for a dataset that spans a large geographic area.
| String |
Code sample
GenerateNearTable example 1 (Python window)
The following demonstrates how to use the GenerateNearTable function in the Python window.
import arcpy
arcpy.env.workspace = "C:/data/input/gnt.gdb"
arcpy.GenerateNearTable_analysis("campsites", ["parks", "trails"], "better_sites")
GenerateNearTable example 2 (stand-alone script)
The following Python script demonstrates how to use the GenerateNearTable function in a stand-alone script.
# Name: GenerateNearTable.py
# Description: Finds 3 nearest in the near feature class from the input feature class.
# import system modules
import arcpy
# set workspace environment
arcpy.env.workspace = "C:/data/input/gnt.gdb"
# set required parameters
in_features = "campsites"
near_features = ["parks", "trails"]
out_table = "near_parks_trails"
# optional parameters
search_radius = '1500 Meters'
location = 'NO_LOCATION'
angle = 'NO_ANGLE'
closest = 'ALL'
closest_count = 3
# find crime locations within the search radius
arcpy.GenerateNearTable_analysis(in_features, near_features, out_table, search_radius,
location, angle, closest, closest_count)
Environments
Licensing information
- Basic: No
- Standard: No
- Advanced: Yes