Modify Underlying Polygon (Production Mapping)
Summary
Determines which polygon features are directly below a line feature. Based on whether the type of feature is valid, which is determined by the subtype or feature class, the tool expands the feature to ensure it meets minimum distance requirements. If it does not meet the minimum distance requirement, the part of the polygon feature under the line is removed and replaced with an appropriate type of feature.
Illustration
Usage
A warning is raised if the input features are not in a projected coordinate system. This tool relies on linear distance units, which will create unexpected results in an unprojected coordinate system. It is strongly suggested that you run this tool on data in a projected coordinate system to ensure valid results. An error is raised and the tool will not process if the coordinate system is missing or unknown.
This tool cannot be run on data that is registered as versioned.
This tool is mainly useful for enhancing the cartographic appearance of data at different scales. For instance, suppose you have powerlines overlaying a vegetation area. If the forest symbol is complex and is composed of several small symbols that represent trees, the points representing the power poles may get lost. To avoid this, you can simplify the symbology by replacing the forest symbol with a more general, solid green symbol so it is still understood that vegetation exists there.
Only polygons that are coincident with line features are affected by this tool.
The buffer distance can be used to ensure that the line can be clearly seen on the map when there are lines and polygons in the same area.
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When replacement features are defined, you can also indicate which features will be created in using the Replace Value (Replace_Value) parameter. For example, if the forest symbol contains a stipple that obscures line features that overlay it, you can replace it with the shrub subtype or the grass feature class, which are represented by solid green symbols.
If this tool is run in an edit session in ArcMap, you can stop the edit session without saving changes to restore features that have been deleted.
Caution:This tool modifies the input data. See Tools with no outputs for more information and strategies to avoid undesired data changes.
Syntax
| Parameter | Explanation | Data Type |
Input_Line_Features | Lines that serve as a reference point for the polygons under them. The tool looks behind these lines to find polygons that need to be modified or deleted. | Feature Layer |
Buffer_Distance |
The minimum distance the edge of the valid polygon features should be from the line. If the polygon is closer than the minimum distance, parts will be deleted until it is within the buffer distance. If the polygon is farther away than the minimum distance, it is expanded until it meets the buffer distance. | Linear units |
Input_Features_Under_Line |
The polygons that will be checked to see if they have features that lie under the lines. | Feature Layer |
Keep_features_underneath_lines (Optional) |
Indicates whether the types of features directly under the lines, based on either the subtype or feature class, are allowed to be under the line or should be replaced.
| Boolean |
Replace_Features (Optional) |
The polygon features that will fill the buffer distance under the line if the features in Input_Features_Under_Line are not valid. | Feature Class |
Replace_Value (Optional) |
The subtype code or description to be assigned to the features in the Replace_Features feature class. | String |
Code Sample
This script modifies facility features under roads.
# Name: ModifyUnderlyingPolygon_Example.py
# Description: Executes Modify Underlying Polygon against LocalGovernment
# sample data
# Author: Esri
# Date: February 2014
# Import arcpy module
import arcpy
# Check out Production Mapping license
arcpy.CheckOutExtension("Foundation")
# Set environment
arcpy.env.workspace="c:/data/LocalGovernment.gdb"
# Define variables
inFeatures="ReferenceData/RoadCenterline"
inFeatureLyr="RoadLayer"
inPolys="ReferenceData/FacilitySite"
inPolysLyr="FaciltyLayer"
bufferIncrease="100 Feet"
replace="REPLACE_FEATURES"
# create feature layers for ModifyUnderlyingPolygon
arcpy.MakeFeatureLayer_management(inFeatures,inFeatureLyr)
arcpy.MakeFeatureLayer_management(inPolys,inPolysLyr)
# execute ModifyUnderlyingPolygon
arcpy.ModifyUnderlyingPolygon_production(inFeatureLyr,bufferIncrease,inPolysLyr,replace)