Once we´ve learned in previous posts how to create routes and calibrate them, let´s see the available tool to generate dynamic segmentation.
This tool allows to create new information layers from a geocodification linked to a linear reference system. For instance, the accident location referred to one road and kp or the representation of capacities or average traffic density of kilometric sections.
To run this tool, it is needed to go from a layer of calibrated routes and one table with columns indicating the kilometric points and columns with other values.
By activating the tool, a dialog box is displayed with the following components:
- “Source” to select the layer of calibrated routes.
- “Route identifier field” to select the table field of the calibrated routes layer containing the identifier of the route.
- “Table” to select the table with values.
- “Route identifier in value table” to select the field of the values table containing the route ID. If it is not selected, either because it does not exist in the table or because it is not desired, all values will be applied to the output for any selected route.
- “Landmark” to indicate the field that will contain the initial kilometer points of each section.
- “Final Landmark” to indicate the field that will contain the final kilometer points of each section.
- “Value” to indicate the field that will contain the values to represent.
- “Output file” to introduce the layer in which all the results will be kept.
Once accepting this dialog, a new layer will be created with the following characteristics:
- If the initial and final landmark fields have been selected, the output layer will be one linear layer with the routes from the original layer separated in the sections indicated by these fields.
- If only the “Landmark” has been selected, the output layer will be a layer of positioned point in the kilometer points indicated by that field.
- In the table associated to the output layer, the new columns will be added:
- “registration” or the name of the column of the table from the original layer where the is the route ID.
- “PK”, if the output layer is a point one, or “PK INICIAL” is a linear one.
- “PK FINAL” if the output layer is linear
- “value” or the name of the column from the value table where is the value aimed to be represented.
After this, any of the gvSIG symbologies for linear layers can be applied.
If, before the tool running, the input layer had any selection, this process only will be applied to the selected routes.
The following image is an example of a linear layer generated by dynamic segmentation. A unique value symbology has been applied using the “VALUE”(TIPO) attribute.
The next image is an example of a point layer generated by dynamic segmentation.
Once the process ends, which will be indicated by a dialog box with a progress bar, gvSIG will give to the user the generated layer in the active view.
- Dynamic segmentation I: https://blog.gvsig.org/2015/11/24/on-the-road-to-gvsig-2-3-dynamic-segmentation-lrs-i/
- Dynamic segmentation (II)/ LRS (I): https://blog.gvsig.org/2015/11/24/on-the-road-to-gvsig-2-3-dynamic-segmentation-lrs-i/
- Dynamic segmentation III. Calibrate Routes: https://blog.gvsig.org/2016/02/22/on-the-road-to-gvsig-2-3-dynamic-segmentation-iii/
- Dynamic segmentation (IV). Editing tool that allows route calibration: https://blog.gvsig.org/2016/02/26/on-the-road-to-gvsig-2-3-dynamic-segmentation-iv/