Reduce Point Density (Maritime)

Summary

Thins points from a point or multipoint feature class.

Using an input feature class with either a numeric depth field or z-enabled geometry, the tool generates an output feature class with a set of points that have been thinned to a user-specified radius in a shallow or deep-biased manner.

Usage

• The tool spatially thins sets of points based on depth values.

• The output layer will be z-enabled if the input is z-enabled.

• If the input is z-enabled, and you want to see the elevation values stored with each point feature, use the Add Z Information tool either before or after using the Reduce Point Density tool to add this information to the attribute table.

• When setting the Start Depth and End Depth parameter values, it may help to know the range of the input depths. To see the range, open the input features attribute table, select the depth field name, and click Statistics.

• To thin depth values from a raster, use the Raster To Point or Raster To Multipoint tool.

• Specify the Start Depth and End Depth parameter values according to the Depth Direction parameter value.

• To run this tool with a thinning radius that remains constant with depth, provide a value for the Start Thinning Radius parameter only. To run the tool with a thinning radius that changes gradually with depth, provide a value for both the Start Thinning Radius and End Thinning Radius parameters.

• The specified thinning radii are approximate in nature. They are intended to honor the Depth Selection Method parameter value and guide the spacing between points preserved in the output.

• Consider using ModelBuilder to chain together multiple runs of this tool to achieve an output in which the thinning radius remains constant for a single depth range but with multiple densities of points created at different depth ranges.

Parameters

Dialog

Label	Explanation	Data Type
Input Features	The input point or multipoint features.	Feature Layer
Output Feature Class	The output feature class.	Feature Class
Depth Field	The field where the depth is stored. It is either a numeric field or the shape field specified in Input Features. Note: For multipoint features, this must be the shape field.	Field
Depth Direction	Specifies how the depth value will be captured in the depth field of the input features. Positive Up—Depth values will be positive above the surface and negative below the surface. This is default. Positive Down—Depth values will be positive below the surface and negative above the surface.	String
Depth Selection Method	Specifies the bias that will be used to select the depths to be retained. Shallow Biased—Shallow bias will be used for depth. This is default. Deep Biased—Deep bias will be used for depth.	String
Thinning Radius Unit	Specifies the unit of measure that will be used by the Start Thinning Radius and End Thinning Radius parameters. Kilometers—The radius unit will be kilometers. Meters—The radius unit will be meters. This is default. Decimeters—The radius unit will be decimeters. Centimeters—The radius unit will be centimeters. Millimeters—The radius unit will be millimeters. Nautical Miles—The radius unit will be nautical miles. Miles—The radius unit will be miles. Yards—The radius unit will be yards. Feet—The radius unit will be feet. Inches—The radius unit will be inches. Decimal Degrees—The radius unit will be decimal degrees. Points—The radius unit will be points.	String
Start Thinning Radius	The beginning radius that will be used to remove or thin points relative to each other.	Double
End Thinning Radius (Optional)	The end radius that will be used to remove or thin points relative to each other. The thinning radius will dynamically change as the algorithm progresses through the range of depth values.	Double
Start Depth (Optional)	The depth that will be used to begin the thinning algorithm. Depth values that appear before this depth based on the Depth Direction parameter value will be ignored.	Double
End Depth (Optional)	The depth that will be used to end the thinning algorithm. Depth values that appear after this depth based on the Depth Direction parameter value will be ignored.	Double

Python

arcpy.maritime.ReducePointDensity(in_features, out_feature_class, depth_field, depth_direction, depth_bias, radius_unit, start_thinning_radius, {end_thinning_radius}, {start_depth}, {end_depth})

Name	Explanation	Data Type
in_features	The input point or multipoint features.	Feature Layer
out_feature_class	The output feature class.	Feature Class
depth_field	The field where the depth is stored. It is either a numeric field or the shape field specified in in_features. Note: For multipoint features, this must be the shape field.	Field
depth_direction	Specifies how the depth value will be captured in the depth field of the input features. POSITIVE_UP—Depth values will be positive above the surface and negative below the surface. This is default. POSITIVE_DOWN—Depth values will be positive below the surface and negative above the surface.	String
depth_bias	Specifies the bias that will be used to select the depths to be retained. SHALLOW_BIASED—Shallow bias will be used for depth. This is default. DEEP_BIASED—Deep bias will be used for depth.	String
radius_unit	Specifies the unit of measure that will be used by the start_thinning_radius and end_thinning_radius parameters. KILOMETERS—The radius unit will be kilometers. METERS—The radius unit will be meters. This is default. DECIMETERS—The radius unit will be decimeters. CENTIMETERS—The radius unit will be centimeters. MILLIMETERS—The radius unit will be millimeters. NAUTICAL_MILES—The radius unit will be nautical miles. MILES—The radius unit will be miles. YARDS—The radius unit will be yards. FEET—The radius unit will be feet. INCHES—The radius unit will be inches. DECIMAL_DEGREES—The radius unit will be decimal degrees. POINTS—The radius unit will be points.	String
start_thinning_radius	The beginning radius that will be used to remove or thin points relative to each other.	Double
end_thinning_radius (Optional)	The end radius that will be used to remove or thin points relative to each other. The thinning radius will dynamically change as the algorithm progresses through the range of depth values.	Double
start_depth (Optional)	The depth that will be used to begin the thinning algorithm. Depth values that appear before this depth based on the depth_direction parameter value will be ignored.	Double
end_depth (Optional)	The depth that will be used to end the thinning algorithm. Depth values that appear after this depth based on the depth_direction parameter value will be ignored.	Double

Code sample

ReducePointDensity example (Python window)

The following Python window script demonstrates how to use the ReducePointDensity function.

import arcpy
arcpy.CheckOutExtension("Bathymetry")
# Input Data
inputData = r"C:\Data\ReducePointDensity\ReducePointDensityTestData.gdb\ENC_Soundings_Delaware"
# Depth Field
depthField = ‘Depth’
# Output Feature Class
outputData = r"C:\Data\ReducePointDensity\ReducePointDensityTestData.gdb\ENC_Soundings_Delaware_Reduced"
arcpy.maritime.ReducePointDensity(inputData, outputData, depthField, ‘POSITIVE_DOWN’, ‘SHALLOW_BIASED’, 'METERS', 1000)
arcpy.CheckInExtension("Bathymetry")

Environments

This tool does not use any geoprocessing environments.

Licensing information

• Basic: No
• Standard: Requires ArcGIS Bathymetry
• Advanced: Requires ArcGIS Bathymetry