I actually am trying to find the distance between two places, I am new to this. I came to know about openstreetmap. But I am not sure what to do.
I found a traveling salesman application that uses osm to route.
But here my question is how to get a osm between places .e.g. "http://www.openstreetmap.org/api/0.6/map?bbox=10,30,10,30" this gives me the map of the box (10,30,10,30) .. but if I want to get the map between leeds and sheffield what should be my query.
Or is there any other way to find the distance.(As I am a student I want some open source way for my academic project..)
please suggest..
You should consider implementing this by yourself.
First, I suggest you to use the Overpass API to do your queries.
Then implement this algorithm over the ways you get from the Overpass API :)
For calculating the routing distance between two places you can use one of the various online or offline routers. There is also a list of various information for routing developers containing a list of libraries and other information.
If you have to obtain the location of a specific address before doing the actual routing you can use Nominatim.
Related
I'm using the Google Distance Matrix API with Java. I want to calculate the train-distance between two cities. One of the cities has no train station. The problem is, google doesn't just calculate the train-distance. It always adds the car-distance from the city without trainstation to the next city with a train station. But for my project i just need the train-distance.
This is a part of my code:
DistanceMatrix matrix = DistanceMatrixApi.newRequest(context)
.origins(origins)
.destinations(destinations)
.mode(TravelMode.TRANSIT)
.transitModes(TransitMode.TRAIN)
.units(Unit.METRIC)
.await();
In the documentation I can't find a solution for this problem.
The Google Maps search algorithms were designed to solve real-world transportation routes, which means that sending a train to a location where the passenger cannot get off is not feasible and therefore not reflected in the routes. I cannot think of any way to extract that information from Google Maps, except possibly doing a direct Directions query, though I doubt it would have different results, since it uses (as far as I can tell) the fundamentally same algorithm for all of its services.
Using a database such as OpenStreetMap (using free, limitless APIs like Overpass to access via HTTP in Java) is probably the best solution. If you want a quick fix, and you are capable of identifying cities without train stations, taking the linear distance between the two cities probably returns a reasonable (though deflated) estimate using the Geometry Library.
Sorry there is not a solution I can see, but this is the best I have.
I'm trying to draw maps similar to these in Java:
I want to auto-generate them from a list of pairs (country,color) to determine the colors. Or (state,color) in the US case. I presume there must be common ways for this, as I find several websites generating them on the fly and sites like wikipedia have several which look exactly the same. But I fail to find information on how to actually generate them. How can I do this?
I want to solve a Travelling Salesman Problem like Google Maps does in its DirectionsRequest with request.setOptimizeWaypoints(true);. It orders some Waypoints in a route so that the travelling-costs are minimal.
My question: Does anybody know which algorithm stands behind it? Any heuristic? Could not find any information by google, so far.
I informed myself and found a lot of insertion-heuristics, nearest neighbour, and so on... Or is it an exact solution procedure?
The Wikipedia page on the Travelling Salesman Problem references a number of algorithms for finding solutions. (But unless N is small, avoid the "exact" algorithms!)
According to this post from a Google employee, the source code for the Googles route calculation algorithms is available here:
http://code.google.com/p/or-tools/source/browse/trunk/examples/cpp/tsp.cc
http://code.google.com/p/or-tools/source/browse/trunk/src/constraint_solver/routing.h
... but it is not entirely clear if this is the "production" code for Google Maps.
From a comment in the source code:
// Solving the vehicle routing problems is mainly done using approximate methods
// (namely local search,
// cf. http://en.wikipedia.org/wiki/Local_search_(optimization)), potentially
// combined with exact techniques based on dynamic programming and exhaustive
// tree search.
This general issue (Google Maps vs TSP) is also discussed in various other SO questions.
References:
Optimal map routing with Google Maps
Travelling Salesman with Google Maps API or any other
What is a practical solution to the Travelling Salesman prblem, using Google Maps?
I am building an sms based application that will retrieve railway schedules.Now the problem that I am facing is that if the user types the wrong name of a particular station(Suppose he writes 'Kolkta' instead of 'Kolkata') then my app would not be able to forward the result of query that has got nearest match to it.How will I do it?Is there an API in java for this?
I guess Apache Lucene provides support you want in java.
Lucence Apache sounds promising, but if you want something more straightforward that you can cook at home very easily, you can try computing the minimal edit distance between the user input and the entire set of railway names. This is a measurement of similarity between strings and can be computed very efficiently (especially in your case, where the strings are very short).
The link above contains a scary mathematical formula but this is the nature of all formal representations. They are scary. Scroll a bit downwards a you will find the extremely short pseudo code for the algorithm (almost copy paste).
Can anyone recommend a Java Graph Visualisation library in which graph nodes can be rendered with multiple connect points?
For example, supposing a graph node represents a processor that takes input from two sources and produces output. This would be visualised as 3 vertices. However, clearly each vertex has a defined role in the workflow and therefore ideally my node would appear with 3 distinct connection points that the user could attach vertices to.
I've taken a look at JUNG but I don't think it will suit my needs.
Any recommendations welcome; either on specific libraries or alternative approaches I can take.
You could try JGraph's java library
JGRAPH
It has a good amount of functionality and I have used it with success before. The only thing is that the documentation is a bit lacking, but if you read through some examples and code its pretty good when you get the hang of it.
Take a look at JGraph (http://www.jgraph.com/). I used jgraph-5.14.0.0 for a similar project before. Here are the graphs that I made for another project: https://github.com/eamocanu/spellcheck.graph/tree/master/graph%20photos