Trace Geometric Network (Data Management)
Summary
Solves the specified network analysis problem based on the flags, barriers, and specified weight properties.
Usage
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This tool does not work with network datasets (the networks used by the ArcGIS Network Analyst extension).
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This tool performs a spatial search using the input flags and barriers to locate coincident features. This is used, in the case of flags, to determine which features the trace should originate from and, in the case of barriers, to determine which features should block the trace. Therefore, the input flags and barriers must be precisely located. In ModelBuilder, if you are uncertain whether the flags and barriers are located correctly, you can use the Snap tool in order to specify with which features the flags and barriers should be coincident.
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The output of this tool is a group layer containing one layer for each feature class contained within the input geometric network. Any features returned from the trace will be selected within their respective layer. When the input layers are present in the map, the output group layer may contain layers without a selection; these are empty layers from which no features were returned from the trace. In ModelBuilder, you can use the Select Data tool to extract specific layers from the group layer and the Make_Feature_Layer tool to create a feature layer from the output of the Select Data tool. Use the Get_Count tool to determine if any of the layers in the group layer are empty. This is especially useful when publishing your model to ArcGIS Server, since group layers are not supported as an output parameter type from a geoprocessing task. Because they aren't supported as direct output, you need to use the Select Data tool to create a single (nongroup) layer for output.
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This tool cannot be run while editing a geometric network in a personal geodatabase.
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Unlike other datasets, such as topology or network datasets, geometric networks do not have an associated layer; therefore, when using this tool in ArcMap, the geometric network must be selected from disk. There is no option to select the geometric network from a layer drop-down list as input.
Syntax
| Parameter | Explanation | Data Type |
in_geometric_network |
The geometric network on which the trace will be performed. | Geometric Network |
out_network_layer |
The name of the group layer that will store the results of the trace as a selected set. | Group Layer |
in_flags |
A point feature class representing a set of flags which serve as starting points for the tracing operation. For example, if you are performing an upstream trace, you use a flag to specify where the upstream trace will begin. Flags can be placed anywhere along edges or junctions, but junctions will be considered first when both a junction and edge are found at the location. | Feature Layer |
in_trace_task_type |
Trace task to be performed on the specified geometric network.
| String |
in_barriers (Optional) |
A point feature class representing a set of barriers defining places in the network, past which, traces cannot continue. If you are only interested in tracing on a particular part of your network, you can use barriers to isolate that part of the network. Barriers can be placed anywhere along edges or junctions, but junctions will be considered first when both a junction and edge are found at the location. The feature will be treated as disabled and will not be considered during the trace, unless you've set the Limit results to features stopping the trace parameter to TRACE_ENDS parameter to purposefully find features stopping the trace. | Feature Layer |
in_junction_weight (Optional) |
A junction weight that is used as a cost for traversing through any junction. The weight must already be defined for the given geometric network. This parameter is disabled or ignored when one of the following cost-independent trace task types is specified:
| String |
in_edge_along_digitized_weight (Optional) |
An edge weight that is used as a cost for traversing through an edge along the digitized direction of that edge. The weight must already be defined for the given geometric network. This parameter is disabled or ignored when one of the following cost-independent trace task types is specified:
| String |
in_edge_against_digitized_weight (Optional) |
An edge weight that is used as a cost for traversing through an edge against the digitized direction of that edge. The weight must already be defined for the given geometric network. This parameter is disabled or ignored when one of the following cost-independent trace task types is specified:
| String |
in_disable_from_trace [in_disable_from_trace,...] (Optional) |
List of feature classes that are disabled from participating in the trace. Specifying a feature class as disabled makes the trace operation treat all features in that feature class as either being disabled or as having a barrier placed on them. Use this option to exclude an entire feature class from consideration during a trace. For example, by disabling the switches layer in an electrical distribution network, setting the Limit results to features stopping the trace parameter to TRACE_ENDS and tracing from a given point in the network, you can find the switches that need to be thrown to isolate this point from the network; these will be the features at which the trace operation is stopped. | String |
in_trace_ends (Optional) | Indicates whether the trace should include all features or only those stopping the trace. Use this option when you need to determine which features are stopping a trace. In order to be returned from the trace operation with this option, features must fall into one of the following categories:
| Boolean |
in_trace_indeterminate_flow (Optional) | Indicates whether the trace should include all features or only those stopping the trace.
Only honored when one flow-dependent trace task type is set:
| Boolean |
in_junction_weight_filter (Optional) |
The weight to use to create the junction weight filter which is used to filter junction features during the trace. | String |
in_junction_weight_range (Optional) |
Specifies valid or invalid ranges of weight values for network features that can be traced. It is disabled when a cost-independent trace task type is set. In order to create a weight filter, you must specify valid weight ranges for the features. A weight filter can be composed of a number of ranges. When you specify multiple weight ranges, you must delimit the ranges with commas. Low and high values in a range are separated by a hyphen. Ranges consisting of a single value do not contain a hyphen and are delimited with commas, for example, 0-2,3,6,7-10. | String |
in_junction_weight_range_not (Optional) | Applies the logical NOT operator to the specified junction weight ranges. By default, the junction weight ranges that you enter specify junction features that can be traced. By checking this option, you indicate that junction features with weights in the ranges you entered cannot be traced.
| Boolean |
in_edge_along_digitized_weight_filter (Optional) |
The weight to use to create the along edge weight filter, which is used to filter edge features during the trace. | String |
in_edge_against_digitized_weight_filter (Optional) |
The weight to use to create the against edge weight filter, which is used to filter edge features during the trace. | String |
in_edge_weight_range (Optional) |
Specifies valid or invalid ranges of weight values for network features that can be traced. It is disabled when a cost-independent trace task type is set. In order to create a weight filter, you must specify valid weight ranges for the features. A weight filter can be composed of a number of ranges. When you specify multiple weight ranges, you must delimit the ranges with commas. Low and high values in a range are separated by a hyphen. Ranges consisting of a single value do not contain a hyphen and are delimited with commas, for example, 0-2,3,6,7-10. | String |
in_edge_weight_range_not (Optional) | Applies the logical NOT operator to the specified edge weight ranges. By default, the edge weight ranges that you enter specify edge features that can be traced. By checking this option, you indicate that edge features with weights in the ranges you entered cannot be traced.
| Boolean |
Code Sample
The following stand-alone Python script demonstrates how to use the TraceGeometricNetwork function in Python scripting to run a Find Connected Trace on a geometric network with Flags and no Barriers.
# Import arcpy module
import arcpy
# Local variables:
gnVersionFDS_Net = "C:/GeometricNetworks/GeometricNetwork.gdb/gnVersionFDS_with_GN/gnVersionFDS_1_Net"
Flags = "C:/GeometricNetworks/GeometricNetwork.gdb/gnVersionFDS_with_GN/Flags"
gnVersionFDS_1 = "gnVersionFDS_1_Net"
# Process: Trace Geometric Network
arcpy.gp.TraceGeometricNetwork(gnVersionFDS_Net, gnVersionFDS_1, Flags, "FIND_CONNECTED", "", "", "", "", "", "NO_TRACE_ENDS", "", "", "", "AS_IS", "", "", "", "AS_IS")
The following stand-alone Python script demonstrates how to use the TraceGeometricNetwork function in Python scripting to run a Find Path Trace on a geometric network with Flags and no Barriers with a weight called Friction_Factor and a weight filter of 1 to 10.
# Import arcpy module
import arcpy
# Local variables:
Water_Net = "C:/GeometricNetworks/Montgomery.gdb/Water/Water_Net"
Flags = "C:/GeometricNetworks/Montgomery.gdb/Water/Flags"
Water_Net_2 = "Water_Net"
# Process: Trace Geometric Network
arcpy.gp.TraceGeometricNetwork(Water_Net, Water_Net_2, Flags, "FIND_PATH", "", "", "Friction_Factor", "Friction_Factor", "", "NO_TRACE_ENDS", "", "", "", "AS_IS", "Friction_Factor", "Friction_Factor", "1-10", "AS_IS")