Archive for the ‘Google Maps’ Category

OptiMap version 4 is here

Wednesday, January 25th, 2012

New user interface

Hold down shift while pressing reload to make sure the page fully reloads if OptiMap appears broken.

The first thing you’ll notice is a complete makeover of the user interface. The functionality has grown considerably since I first posted OptiMap in 2007, and the controls were scattered randomly around. Now, they are organized into neat little drawers on the left, in the order you are likely to be using them. (more…)

The Dynamic Programming Algorithm for the Travelling Salesman Problem

Friday, June 24th, 2011

A reader asked me for some information on how the dynamic programming algorithm for the TSP works. I was surprised to find that a Google search found no good resources. Wikipedia merely acknowledges its existence: “One of the earliest applications of dynamic programming is the Held–Karp algorithm that solves the problem in time O(n22n).” (more…)

OptiMap for Google Maps v3 released

Friday, June 3rd, 2011

Manhattan with 100 destinations

After being “almost ready” for way too long, the next version of OptiMap, based on Google Maps API version 3, is now launched. While I have tested most aspects of the application, there are most likely bugs, since the update touched almost all areas of the code. There are some improvements too, however:

  • More robust address lookups (a lot of people experienced a “failed to geocode” error when entering many addresses. This was due to too many requests in a short period of time, and a queue-system has been added to avoid this from happening. The lookups may take slightly longer due to this.
  • Progress indicator for directions lookups. Because version 3 of the Google Maps API only allows 10 waypoints in a single request (down from 25 in the previous version), this part is now a bit slower, so a progress indicator is needed.
  • Tuning of the solver code based on faster browsers becoming more common. This should improve the quality of the solutions for cases with more than 15 locations.

Please help me solve any bugs that you may encounter by posting a comment on this site. Information that will be helpful when locating the bug includes:

  • Browser (with version if possible)
  • List of addresses or locations and a description of how to reproduce the bug
  • The output that you see (error message, why you think the solution is wrong etc.)

Japan Radiation Map

Thursday, March 17th, 2011

Japan Radiation Map at 2011-03-17 18:40:00 Japan local time

I’ve created a map which shows the measured radiation values in Japan (note that this map is no longer online – the rest of this post is out of date). The data is scraped (credits go to Marian Steinbach) every 10 minutes (hit refresh to get the newest data). You can also click on each measurement location to see a chart of the measurements from that station over time.

Chart of historical values

Currently, there are about 200 measurement stations, but I’m having trouble finding the latitude and longitude of each measurement station. I’m sure someone who knows Japanese would have more luck…Anyway, I’m slowly working my way through the list of measurement stations, so more locations will be added continously. Any help with this would be much appreciated. Feedback and criticism is welcome, and should be added as comments to this page.

Update 2011-03-20: With the help of volunteer “hosoyamane”, a Japanese translation of the map is now available. It’s great to see volunteers pop up so fast!

Update 2011-03-20: A small spike in radiation is showing up in the stations in the Ibaraki prefecture around 10 am Japan local time this morning. However, the levels are still low (1000 nano-Gray is still 2000 times less than the average yearly dose of background radiation).

Update: The original radiation map I created is no longer maintained. Instead, users are redirected to a map created by the Institute of Information Design of Japan.

OptiMap + TomTom = Powerful Routing Application

Saturday, March 14th, 2009

I’m finally announcing the most requested feature on OptiMap: The ability to export itineraries easily to TomTom GPS navigation devices. GPSes are becoming standard in cars, and are invaluable to anyone who is doing deliveries or needs to visit unfamiliar locations. Those people often go to many places in a single day, and can benefit greatly from OptiMap in terms of time and gas saved.

In-car navigation systems have several advantages over printed directions:

  • No need to stop and look at a map / textual directions
  • You know where you are all the time
  • If you make a wrong turn, you get re-routed
  • No paper and ink wasted

To send directions to your TomTom device, do the following:

  1. Make sure you have TomTom HOME installed.
  2. Use OptiMap to calculate your trip as you normally would.
  3. A new button labeled ‘Send to TomTom’ appears above the driving directions. Click it.
  4. Click the ‘+TOMTOM’ button that appears in a new page. This will launch the TomTom HOME application showing the route.
  5. Follow instructions in the TomTom HOME application to install the itinerary on your device.

Please also note that I coded this solution completely in the dark, since I do not have a TomTom GPS. This means that I have not personally tested how the solution works on various real devices. Below is a list of devices that have been tested by various visitors of this site.

  1. TomTom GO 720 (itinerary download works, have not navigated route yet)

Please post a reply to this thread if you have tested devices not listed above, or if you encounter problems.