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Overlay Route Events (Linear Referencing)
Release 9.2 Last modified November 9, 2006	Print all topics in : "Tools"

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Overlays two event tables to create an output event table that represents the union or intersection of the input.

Usage tips

Line on line, line on point, point on line, and point on point event overlays can be performed.
The input and overlay events should be based on the same route reference.
If both the input and overlay event properties are type POINT, the output event properties must also be defined as type POINT.
If both the input and overlay event properties are type LINE, the output event properties must also be defined as type LINE.
If either the input or overlay event properties are type POINT, the output event properties must be defined as type POINT when an INTERSECT overlay is performed. The output event properties must be defined as type LINE when a UNION overlay is performed.
If both the input and overlay event properties are type POINT, only the points that have the exact same measure value are considered to intersect. There is no search tolerance.
The input tables can be any type of table ArcGIS supports. The output table can be a dBASE file or a geodatabase table.
An attribute index on the route identifier field speeds up the dynamic segmentation process. If you will be using the Output Route Feature class for dynamic segmentation, it is recommended that you choose to have an attribute index created.
Use Make Table View prior to Overlay Route Events to effectively reduce the number of events that will be processed.
If either the input or overlay events do not have an ObjectID field, use Make Query Table prior to Overlay Route Events to add a virtual ObjectID field.
The output table can be displayed in ArcMap using Make Route Event Layer or the Add Route Events dialog box.
Learn more about overlaying event data
The following environments affect this tool: configKeyword, scratchWorkspace, and workspace.

Command line syntax
An overview of the Command Line window
OverlayRouteEvents_lr <in_table> <in_event_properties> <overlay_table> <overlay_event_properties> <INTERSECT | UNION> <out_table> <out_event_properties> {ZERO | NO_ZERO} {FIELDS | NO_FIELDS} {INDEX | NO_INDEX}

Parameter	Explanation	Data Type
<in_table>	The input event table.	Table View
<in_event_properties>	Parameter consisting of the route location fields and the type of events in the input event table. Route Identifier Field — The field containing values that indicate which route each event is along. This field can be numeric or character. Event Type — The type of events in the input event table (POINT or LINE). POINT — Point events occur at a precise location along a route. Only a from-measure field must be specified. LINE — Line events define a portion of a route. Both from- and to-measure fields must be specified. From-Measure Field — A field containing measure values. This field must be numeric and is required when the event type is POINT or LINE. To-Measure Field — A field containing measure values. This field must be numeric and is required when the event type is LINE.	Route Measure Event Properties
<overlay_table>	The overlay event table.	Table View
<overlay_event_properties>	Parameter consisting of the route location fields and the type of events in the overlay event table. Route Identifier Field — The field containing values that indicate which route each event is along. This field can be numeric or character. Event Type — The type of events in the overlay event table (POINT or LINE). POINT — Point events occur at a precise location along a route. Only a from-measure field must be specified. LINE — Line events define a portion of a route. Both from- and to-measure fields must be specified. From-Measure Field — A field containing measure values. This field must be numeric and is required when the event type is POINT or LINE. To-Measure Field — A field containing measure values. This field must be numeric and is required when the event type is LINE.	Route Measure Event Properties
<INTERSECT \| UNION>	The type of overlay to be performed. INTERSECT — Write only overlapping events to the output event table. This is the default. UNION — Write all events to the output table. Linear events are split at their intersections.	String
<out_table>	The table to be created.	Table
<out_event_properties>	Parameter consisting of the route location fields and the type of events that will be written to the output event table. Route Identifier Field — The field that will contain values that indicate which route each event is along. Event Type — The type of events the output event table will contain (POINT or LINE). POINT — Point events occur at a precise location along a route. Only a from-measure field must be specified. LINE — Line events define a portion of a route. Both from- and to-measure fields must be specified. From-Measure Field — A field that will contain measure values. Required when the event type is POINT or LINE. To-Measure Field — A field that will contain measure values. Required when the event type is LINE.	Route Measure Event Properties
{ZERO \| NO_ZERO}	Specifies whether to keep zero length line events in the output table. This parameter is only valid when the output event type is LINE. ZERO — Keep zero length line events. This is the default. NO_ZERO — Do not keep zero length line events.	Boolean
{FIELDS \| NO_FIELDS}	Specifies whether all the fields from the input and overlay event tables will be written to the output event table. FIELDS — Include all the fields from the input tables in the output table. This is the default. NO_FIELDS — Do not include all the fields from the input tables in the output table. Only the ObjectID and the route location fields are kept.	Boolean
{INDEX \| NO_INDEX}	Specifies whether an attribute index will be created for the route identifier field that is written to the output event table. INDEX — Create an attribute index. This is the default. NO_INDEX — Do not create an attribute index.	Boolean

Data types for geoprocessing tool parameters

Command line example

Workspace D:\Data\pitt_county
OverlayRouteEvents_lr accident.dbf "rkey POINT mile" pavecond.dbf "rkey LINE fmp tmp" INTERSECT accpav.dbf "rkey POINT mile"

Workspace D:\Data\pitt_county\Pitt.mdb
OverlayRouteEvents_lr pavecond "rkey LINE fmp tmp" pavetype "rkey LINE fmp tmp" "UNION" condtype "rkey LINE fmp tmp" NO_ZERO

Workspace D:\Data\pitt_county\Pitt.gdb
OverlayRouteEvents_lr pavecond "rkey LINE fmp tmp" pavetype "rkey LINE fmp tmp" "UNION" condtype "rkey LINE fmp tmp" NO_ZERO

Workspace "Database Connections\Connection to Jerry.sde"
OverlayRouteEvents_lr gdb.accident "rkey POINT mile" gdb.pavecond "rkey LINE fmp tmp" INTERSECT accpav "routekey POINT milepost"

Scripting syntax
About getting started with writing geoprocessing scripts
OverlayRouteEvents_lr (in_table, in_event_properties, overlay_table, overlay_event_properties, overlay_type, out_table, out_event_properties, zero_length_events, in_fields, build_index)

Parameter	Explanation	Data Type
in_table (Required)	The input event table.	Table View
in_event_properties (Required)	Parameter consisting of the route location fields and the type of events in the input event table. Route Identifier Field — The field containing values that indicate which route each event is along. This field can be numeric or character. Event Type — The type of events in the input event table (POINT or LINE). POINT — Point events occur at a precise location along a route. Only a from-measure field must be specified. LINE — Line events define a portion of a route. Both from- and to-measure fields must be specified. From-Measure Field — A field containing measure values. This field must be numeric and is required when the event type is POINT or LINE. To-Measure Field — A field containing measure values. This field must be numeric and is required when the event type is LINE.	Route Measure Event Properties
overlay_table (Required)	The overlay event table.	Table View
overlay_event_properties (Required)	Parameter consisting of the route location fields and the type of events in the overlay event table. Route Identifier Field — The field containing values that indicate which route each event is along. This field can be numeric or character. Event Type — The type of events in the overlay event table (POINT or LINE). POINT — Point events occur at a precise location along a route. Only a from-measure field must be specified. LINE — Line events define a portion of a route. Both from- and to-measure fields must be specified. From-Measure Field — A field containing measure values. This field must be numeric and is required when the event type is POINT or LINE. To-Measure Field — A field containing measure values. This field must be numeric and is required when the event type is LINE.	Route Measure Event Properties
overlay_type (Required)	The type of overlay to be performed. INTERSECT — Write only overlapping events to the output event table. This is the default. UNION — Write all events to the output table. Linear events are split at their intersections.	String
out_table (Required)	The table to be created.	Table
out_event_properties (Required)	Parameter consisting of the route location fields and the type of events that will be written to the output event table. Route Identifier Field — The field that will contain values that indicate which route each event is along. Event Type — The type of events the output event table will contain (POINT or LINE). POINT — Point events occur at a precise location along a route. Only a from-measure field must be specified. LINE — Line events define a portion of a route. Both from- and to-measure fields must be specified. From-Measure Field — A field that will contain measure values. Required when the event type is POINT or LINE. To-Measure Field — A field that will contain measure values. Required when the event type is LINE.	Route Measure Event Properties
zero_length_events (Optional)	Specifies whether to keep zero length line events in the output table. This parameter is only valid when the output event type is LINE. ZERO — Keep zero length line events. This is the default. NO_ZERO — Do not keep zero length line events.	Boolean
in_fields (Optional)	Specifies whether all the fields from the input and overlay event tables will be written to the output event table. FIELDS — Include all the fields from the input tables in the output table. This is the default. NO_FIELDS — Do not include all the fields from the input tables in the output table. Only the ObjectID and the route location fields are kept.	Boolean
build_index (Optional)	Specifies whether an attribute index will be created for the route identifier field that is written to the output event table. INDEX — Create an attribute index. This is the default. NO_INDEX — Do not create an attribute index.	Boolean

Data types for geoprocessing tool parameters

Script example

# Example 1:
#   Point-on-line INTERSECT overlay (both tables are dBASE)

import arcgisscripting, constants
gp = arcgisscripting.create()
try:
    gp.Workspace = "D:/Data/pitt_county"
    in_tbl = "accident.dbf"
    in_props = "rkey POINT mile"          # reused as out event properties
    ov_tbl = "pavecond.dbf"
    ov_props = "rkey LINE fmp tmp"
    out_tbl = "accpav"
    gp.OverlayRouteEvents_lr (in_tbl, in_props, ov_tbl, ov_props, "INTERSECT",                               out_tbl, in_props)
except:
    print gp.GetMessages(2)


# Example 2:
#   Line-on-line UNION overlay (both tables are in a file geodatabase)

import arcgisscripting, constants
gp = arcgisscripting.create()
try:
    gp.Workspace = "D:/Data/pitt_county/Pitt.gdb"
    in_tbl = "pavecond"
    in_props = "rkey LINE fmp tmp"          # reused as overlay and out event properties
    ov_tbl = "pavetype"
    out_tbl = "condtype" 
    gp.OverlayRouteEvents_lr (in_tbl, in_props, ov_tbl, in_props, "UNION",                               out_tbl, in_props, "NO_ZERO")
except:
    print gp.GetMessages(2)


# Example 3:
#   Line-on-line UNION overlay (both tables are in a personal geodatabase)

import arcgisscripting, constants
gp = arcgisscripting.create()
try:
    gp.Workspace = "D:/Data/pitt_county/Pitt.mdb"
    in_tbl = "pavecond"
    in_props = "rkey LINE fmp tmp"          # reused as overlay and out event properties
    ov_tbl = "pavetype"
    out_tbl = "condtype" 
    gp.OverlayRouteEvents_lr (in_tbl, in_props, ov_tbl, in_props, "UNION",                               out_tbl, in_props, "NO_ZERO")
except:
    print gp.GetMessages(2)


# Example 4:
#   Point-on-line INTERSECT overlay (both tables are in enterprise geodatabase)

import arcgisscripting, constants
gp = arcgisscripting.create()
try:
    wkspc = "Database Connections/Connection to Jerry.sde"
    gp.Workspace = wkspc
    in_tbl = gp.QualifyTableName("accident", wkspc)
    in_props = "rkey POINT mile"  
    ov_tbl = gp.QualifyTableName("pavecond", wkspc) 
    ov_props = "rkey LINE fmp tmp"
    out_tbl = "accpav"
    out_props = "routekey POINT milepost"     # names are changed for out table
    gp.OverlayRouteEvents_lr (in_tbl, in_props, ov_tbl, ov_props, "INTERSECT",                               out_tbl, out_props)
except:
    print gp.GetMessages(2)

Overlay Route Events (Linear Referencing)

Command line example

Script example