Real-world analytics for Analytics 2013!

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You might have seen my previous blog, where I plotted some interesting tourist attractions on a geographical map of the British Isles (which may be of interest to Analytics 2013 Conference delegates)...

Well this blog uses even more powerful analytics, and shows how SAS can calculate the "optimal tour" to visit all the locations using the TSP statement in SAS/OR’s PROC OPTNET (the TSP statement invokes an algorithm that solves the traveling salesman problem).

 

First I generate every pair of locations (attractions), using PROC SQL.  And while doing that, I also calculate the distance (in miles) between the latitude/longitude coordinates using the geodist function:

proc sql;
create table pairs as select
a.attraction as attraction1, a.lat as lat1, a.long as long1,
b.attraction as attraction2, b.lat as lat2, b.long as long2,
geodist(lat1, long1, lat2, long2, 'DM') as distance
from attractions as a, attractions as b
where a.attraction < b.attraction;
 

Now we can ask PROC OPTNET to find the optimum tour (via the TSP statement), using the distance as the 'weight':

proc optnet  data_links=pairs  out_nodes=PathOrder;
data_links_var  from=attraction1  to=attraction2  weight=distance;
tsp  out=Path;
 
(And, of course, this example assumes you can go straight from one tourist attraction to the next, using a helicopter or other James Bond-like flying device!) 

The rest of the code is just 'details' - using annotate move/draw functions to connect the points and such!

Did you know SAS could do this kind of "geographical analytics?" Perhaps you have some data you could analyze with the new PROC OPTNET?...

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About Author

Robert Allison

The Graph Guy!

Robert has worked at SAS for over 25 years, and is perhaps the foremost expert in creating custom graphs using SAS/GRAPH. His educational background is in Computer Science, and he holds a BS, MS, and PhD from NC State University. He is the author of several conference papers, has won a few graphic competitions, and has written a book (SAS/GRAPH: Beyond the Basics).

4 Comments

  1. Pingback: Tourist attractions near Analytics 2013 London | SAS Training Post

    • Robert Allison
      Robert Allison on

      Efficiency is one of the major goals in all of the SAS procedures! The SAS/OR 12.1 User's Guide says: "The underlying algorithms are highly efficient and can successfully address problems of varying levels of detail and scale."

      For this particular example, Proc Optnet runs (on my laptop PC) in less than a second, as indicated in the SAS log ... "Processing the traveling salesman problem used 0.95 (cpu: 0.11) seconds".

  2. Pingback: How could SAS be used to help find missing planes like Flight 370?

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