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The Trace Out tool, located on Tools Menu > Show Map Editing Tools > Advanced Tools > Reporting, is used to analyze polyline connectivity. Pick a starting point and the tool will trace along all connected polylines in all direction to determine the extent of the network. Tracing passes from one polyline to the next only if the polylines connect at their end points. A polyline that T's into another or crosses another at a mid point are not considered to connect. The resulting report is a layer highlighting all traced lines in yellow with all termination points marked with a red diamond.
Select Layer
When running the tool, users will be prompted to specify one or more layers that form the polyline network. All polylines will be analyzed for connectivity as if they were all on the same layer.
Select Trace Direction
With Flow When this option is selected, Think GIS will only trace polylines in the direction that they were drawn (down stream). The direction of a polyline can only be revealed when setting the line style of the layer to the arrow line style. One example of doing a "With Flow" trace might be to select a storm water grate as the starting point and check to see if the path makes it all the way to the anticipated discharge point. If not, some broken lines or lines are drawn in the wrong direction.
Against Flow With this option Think GIS will only trace polylines in the opposite direction that they were drawn (up stream). One example of doing an "Against Flow" trace might be to select the sewage treatment plant as the starting point to confirm that the trace covers the entire network. This of course assumes that all pipes should flow to the same treatment plant.
Any Direction Use this option to check general connectivity of the polyline network. Tracing will be done in all directions and any breaks will be indicated on the report.
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