MapInfo Pro

 View Only
Back to discussions
Expand all | Collapse all

MapInfo Monday: Connecting Points to Illustrate Movement II

  • 1.  MapInfo Monday: Connecting Points to Illustrate Movement II

    Employee
    Posted 23 days ago

    In last week's article MapInfo Monday: Connecting Points to Illustrate Movement, we connected several observations with lines to illustrate how something had moved across an area.

    We used simple lines to show this movement but people rarely fly across the area like crows. They typically use the existing road network - especially if they drive in cars.

    This week, we look at using MapInfo RouteFinder to calculate routes between the observations to get an idea of what route they may have taken between the points.

    The map below shows the observations connected with straight lines.

    RouteFinder

    RouteFinder is an application for MapInfo Pro for users looking to solve route-related problems. RouteFinder can of course do the typical point-to-point route calculation and also solve the Travelling Sales Person (TSP) problem which we will be using today. But it does much more such as calculating isochrones and distance matrices, running cluster analysis, and service area calculations. Just to name a few.
    After loading RouteFinder you also have to set the Network that you want RouteFinder to use. A Network is a precalculated file that gives RouteFinder information about how to travel through your road network.
    From the RouteFinder tab, click on Open Network control.
    In the Open Network dialog, select the MapInfo TAB file related to the network. If no networks are shown in the list, use the Select table to open button to open a MapInfo TAB file that has a related network.
    Precisely can provide networks and streets for a long list of countries across the world that have been created to be used in RouteFinder. You can also create the network from an existing road network table
    Now that we have opened the network, RouteFinder is ready to use.
    In our example, we already know the order of the points we want to calculate a route between. To ensure this order is correct in the table, I run a query to order the records by the STOPID column using the Simple Select dialog.
    After this, I save the sorted table into a new table called ObservationsSorted and open this in MapInfo Pro.

    Calculating route using Travelling Sales Person

    To calculate a route between several points in a table, we will use the TSP by Table option in RouteFinder. From the Optimise dropdown on the RouteFinder tab, I select TSP by Table control.
    In the TSP from Table dialog, I need to make a few changes. First, I'll select my table holding the ordered observations. And secondly, I need to check the Points order already optimised control telling the process that it needs to keep the order of the points in my table.
    This will make the TSP from Table process calculate a route between the first and the second point, the second and the third point, the third and the fourth point, and so on. If I didn't check this option, the process would optimise the order of the points to find the optimal route.
    When the process is finished, you will be shown a browser window of the ObservationsOrdered table. The column RF_Order has been added by RouteFinder during the process if it isn't already there. This column holds the order of the visits to the points in the table.
    The calculated route will also be added to the map. This shows you the route that has been chosen between the observations.

    Fastest versus Shortest Route

    When you do routing calculations, you can typically choose to calculate the fastest or the shortest route. This is also possible with RouteFinder.
    In the Route Options dialog, you can select between Shortest and Fastest under Calculation.
    In the map below, you can see how the route differed depending on the calculation method.
    If you look at the details in the table theRoute, you can find more information calculated by the RouteFinder. This is details about the time and length of the route and segment.
    I hope this gave you some ideas on how to use RouteFinder to analyze possible routes between observations.
    Happy #MapInfoMonday!


    ------------------------------
    Peter Horsbøll Møller
    Principal Presales Consultant | Distinguished Engineer
    Precisely | Trust in Data
    ------------------------------