An optimal tour for nl57912 is given in the following files. The files describe the same tour, but use different data formats to list the order the Dutch national monuments are visited.
• nl57912_order.txt, the (latitude-longitude) locations for nl57912 permuted in optimal order,
• nl57912_tour.txt, a list of integers from 1 up to 57,912, giving the order the points appear in the tour (the numbers correspond to positions in the lat-long data set given on the Data page),
• nl57912.tour, the tour in TSPLIB format,
• nl57912.gpx.gz, the tour in (gzipped) GPX format, commonly used by cycling computers.
The tour has length 20,253,062 meters, measured using the table of point-to-point biking distances computed by CQM.
Note that the distance data is symmetric, that is, the distance from monument A to monument B is the same as the distance from B back to A. So you may travel around the tour in either the forward or backward directions.
The above files specify the tour, but they do not give much intuition for the route taken through the Netherlands. Not to worry. Team CQM has it covered. They put together an interactive map, allowing you to examine the tour in detail, zooming and panning around the countryside.
We list below two versions of the map. The first has markers for the monuments arranged in clusters, that expand into smaller clusters and eventually into individual markers as you zoom in for a closer look. The second displays all 57,912 markers at the same time. For this display, the map initially looks like a blue blob, but the circular markers spread out nicely as you zoom into the view.
• nl57912_map_cluster.html, map with expanding clusters of monuments,
• nl57912_map_markers.html, map with the full set of markers.
Note: The maps look great in the Chrome, Edge, and Firefox browsers, but they do not render correctly in Safari. Sorry!
Click on the images to see high-resolution snapshots.
