I'm writing a Rails backend for a mobile project and I've come across a pretty interesting problem.
I want to calculate the time of arrival between two points by car (with given points A and B) in what time A could arrive to point B. The reason why I do not take distance as a metric is because in terms of bird's eye view, the shortest distance doesn't always give you an accurate answer. Since traffic rules apply the vehicle A might be real close to point B but due to the available turns and etc. the vehicle C that is actually far more behind than the C could have a less time of arrival.
Of course using Google Maps API is the first and a pretty neat solution, however I consider that constantly querying the maps API could slow down the server, making my backend solution in efficient.
Would there be an alternative solution in order to provide an accurate time of arrival considering the real life complications such as turns, traffic and etc.
The directions service is included in the google maps API, just like geolocation. IF you can use one, you can use the other. From a google serach : https://developers.google.com/maps/documentation/directions/
Related
So I am very fascinated about the bet365 real time match updates.
I m impressed how they have managed to show the attack and the defense as well as the real time ball passing stats. I really want to know more on how this work and is it possible to implement a similar.
Could someone help ??
All live informations about match has bet365 from external services, that provide those informations. There are many services, that provide those data (for example betradar)
I'm working with a project its related to Offline map application.Because of that I searched for offline map which shows the defined area. I used MapBox for offline mapping. I can add annotation on this map and draw lines.
But my requirement is offline map with routing. I was fed up to find a offline routing library or offline routing engine to embedded to Xcode.
Appreciate if any of you have any clue or sample project/code to implement this
Note : This question is related to my one. No one replied to this as well
Thanks.
Offline implies no internet, the iPhone is still able in most cases to get the users current location from the GPS. That means that you can be quite confidant that you can find out the current location of the user whilst offline.
The problem with offline routing is that the Phone is dumb, it only remembers the x amount of MB of data in terms of tiles to display.
Routing is something completely different, it takes a point A and B and works out the shortest, fastest, cheapest or all of those between A and B.
This takes a lot more then tiles to accomplish, after all if you think in terms of MVC, tiles are just the dump views, they don't know much about what's around them except what's inside of them. It would be the "controller" who would calculate routes, and for that you would need to be in possession of all the data spanning the desired area for routing.
For each mapping service you will find a different route, maybe not in terms of actual path, but in estimated time, effort etc, what this means is that if you have your own maps (offline in a database), it's up to you to use that data, so you should make your own routing algorithm which I'm sure isn't what you want to do.
So what are your options? At the moment this just isn't possible in the scope you want. Even if you had an offline maps database, you still need a routing algorithm.
In offline case also you can get the current location by using only GPS and you can draw overlay lines from current location to the interesting point for that you have to do some calculations
You can make offline routing by using graphhopper library by making graph data which contains (Street names, routes,edges) . Graph data is taken by .pbf file which can be taken by (Use this:http://download.geofabrik.de) and use commands(in Terminal) that was given by (https://github.com/graphhopper/graphhopper-ios/tree/master/graphhopper-ios-sample) to convert .pbf into graph data. Then we can make offline routing with its instruction (All given in graphhopper iOS sample).please refer that carefully. because i have done and finish my project successfully.
I am developing iOS 5 app which I want to communicate with server providing information about the nearby places for a given location: places locations and annotations. I want to use MapKit to populate my map with this information.
I didn't find any straightforward information regarding the following questions:
Does MapKit has tiles functionality (Google Maps way) out-of-the-box and do I need to work on it additionally, if not?
What is the best practice of retrieving places information (markers positions and annotations) from server?
Is it possible to cache this information so an user can see the nearby places of "his city" in offline mode?
Actually questions 2 and 3 are interrelated: they both address the problem of not retrieving an information (locations + annotations) that is already on map multiple times.
Hopefully I am not overlooking something obvious here.
Thanks!
Update 1: (Regarding places, not maps) More specifically I am interested in, how should I create a "hand-crafted" logical tiles for regions containing the places I fetch from the server, so they would not require refetching themselves when user scrolls the map? I know I can dive into implementing this functionality myself. For example, should I write the places just fetched to a local storage using Core Data immediately after fetching them or organize some queue? Or how could I know when I need to perform a request about the specific region on server and when I just fetch local data that is already on the device? I just want to know, are there any recommended approaches, best practices? Hopefully, I wrote it clear here.
Update 2: I am wondering about best practices here (links, example) not to start creating all this (points 2+3) from scratch. Are there any frameworks incapsulating this or good tutorials?
#Stanislaw - We have implemented the functionality you describe in an app called PreventConnect for one of our clients. The client already had some data stored out in a Google Fusion table. We extended their existing solution by adding another Google Fusion table which stores the geocoordinates for a number of locations. All this being said, to answer your questions...
1) The map portion itself is pretty out of the box, the tiles and what not, but you'll need to do some coding to get zoom extents, pin drops, annotations, and things like that working the way you expect them to work.
2) We found the Google Fusion solution to be quite effective. If you don't want to use Google Fusion there are other cloud database providers like StackMob, database.com, and many others. Google is free and they have an iOS SDK that makes communicating with Google Fusion pretty simple.
3) Absolutely! We cache much of the data in a Core Data store locally on the device. This greatly improves performance and responsiveness.
Time to write a solid answer to this my question (I could have it written a year ago but somehow I lost it from my mind).
Does MapKit has tiles functionality (Google Maps way) out-of-the-box and do I need to work on it additionally, if not?
The answer is yes: MapKit does have it. The keywords here are overlays (MKOverlay, MKOverlayView and others). See my another answer.
See also:
WWDC 2010 Session: Customizing Maps with Overlays,
Apple-WWDC10-TileMap.
What is the best practice of retrieving places information (markers positions and annotations) from server?
Actually since then I didn't learn a lot about "best practices" - unfortunately, nobody told me about them :( - that is why I will describe "my practices".
First of all, there are two strategies of populating a MapKit map with places:
The first strategy is about populating your map with the places by demand: imagine you want to display and see all places nearby (for example, no more than 1km from current user location) - this approach assumes that you ask your server only the places for the box you are being interested in. It means something like: "if I am in Berlin (and I expect 200 places for Berlin), why should I ever fetch the places from Russia, Japan, ... (10000+ places)".
This approach leads to relying on "tiles" functionality that question N1 address: Google maps and Apple maps are usually drawn using 'tiles' so for your "Berlin" portion of map you rely on corresponding "Berlin" tiles that are drawn by MKMapView - you use their dimensions, to ask your server only the places within the "Berlin" box (see my linked answer and the demo app there).
Initially this was the approach I've used and my implementation worked perfectly but later I was pushed to use second approach (see below) because the problem of clustering appeared.
The second strategy is to fetch all the places at once (yeah, all this 10000+ or more) and use Core Data to fetch the places needed for the visible portions of map your are interested in.
Second approach means, that during the first run you send your server a request to fetch all places (I have about 2000 in my app). Important here is that you restrict the fields you fetch to only geo-ones that you really need for your map: id, latitude, longitude.
This 'fetch-all' fetch has a significant impact on my app's first start time (On "the oldest" iPhone 4, I have near 700ms for the whole Fetch + Parse-JSON-into-Core-Data process, and extensive benchmarks show me that it is Core Data and its inserts is a bottleneck) but then you have all the essential geo-info about your places on your device.
Note, that whatever strategy you use, you should do a process of fetching these geo-points efficiently:
Imagine Core Data entity Place which has the following fields structure (preudo-Objective-C code):
// Unique identificator
NSNumber *id,
// Geo info
NSNumber *latitude,
NSNumber *longitude,
// The rest "heavy" info
NSString *name,
NSString *shortDescription,
NSString *detailedDescription, etc
Fetching places efficiently means that you ask only your place records geo-data from your server to make the process of this mirroring as fast as possible.
See also this hot topic: Improve process of mirroring server database to a client database via JSON?.
The clustering problem is out of scope of this question but is still very relevant and affects the whole algorithm you use for the whole proces - the only note I will leave here is that all the current existing clustering solutions will require you to use second strategy - you must have all the places prepared before you run into the clustering algorithms that will organize your places on a map - it means that if you decide to use clustering you must use strategy #2.
Relevant links on clustering:
WWDC 2011 Session: Visualizing Information Geographically with MapKit,
How To Efficiently Display Large Amounts of Data on iOS Maps,
kingpin - Open-source clustering solution: performant and easy-to-use.
Is it possible to cache this information so an user can see the nearby places of "his city" in offline mode?
Yes, both strategies do this: the first one caches the places you see on your map - if you observed Berlin's portion of map you will have Berlin part cached...
When using the second strategy: you will have all essential geo-information about your places cached and ready to be drawn on a map in offline mode (assuming that MapKit cached the map images of regions you browse in offline mode).
I'm working on an iOS app that pulls events from Google Calendar and subsequently generates pins on a map for each event (based on what the event creator fills in for "Location"). The user can select a date range (today, this week, this month, etc.) and see all the events taking place near them over that period.
Problem 1: The app is for my local university, so a majority of the locations will be buildings on campus. These buildings have inconsistent addresses that are often difficult to find, so it would be good if the location "Foo Hall" would result in a pin on that building. Google Maps is capable of doing this, however Apple Maps has no knowledge of the buildings on my school campus.
Problem 2: In an ideal situation, thousands of students would be using this app. Each time they open the app, they could be viewing dozens of pins. Therefore, I'm worried that I may be pushing the limits imposed by Google's geocoding API (definitely the 2500 request limit, and maybe even the 100,000 request limit for the Business API).
So my question is... what would be the best solution for these two problems? Should I create a local database for building names and map them to coordinates? Or is there a way I can overcome the limitations of Google's Geocoding API? Is there a better solution I'm not thinking of?
Thanks for any help!
I would use latitude and longitude coordinates for the buildings and allow for people to add locations to the database if they are meeting somewhere that you have not added already. This way, the pins will drop in the center of the building if you want them to, because you are not relying on an address or on looking up a building name. You simply know that "Foo Hall" is at X latt. and Y long. And if someone selects "Foo Hall" or sees an event at "Foo Hall" there is a perfectly placed pin right in the middle of it on the map. I don't think you need to worry as much about the geocoding API if you are using hardcoded locations for the buildings either, because you won't have to be polling Google to get the building locations.
I would also use some sort of server to store the building locations so they can be updated or added to, either by you or by the users.
That's how I would handle it, good luck!
I'm working on a project that returns information based on the user's location. I also want to display the user's town in text (no map) so they can change it if it's not accurate.
If things go well I hope this will be more than a small experiment, so can anyone recommend a good reverse geocoding service with the least restrictions? I notice that Google/Yahoo have a limit to the number of daily queries along with other usage terms. I basically need to take latitude and longitude and convert them to a city/town (which I presume cannot be done using the HTML5 Geolocation API).
Geocoda just launched a geocoding and spatial database service and offers up to 1K queries a month free, with paid plans starting at $49 for 25,000 queries/month. SimpleGeo just closed their Context API so you may want to look at Geocoda or other alternatives.
You're correct, the browser geolocation API only provides coordinates.
I use SimpleGeo a lot and recommend them. They offer 10K queries a day free then 0.25USD per 1K calls after that. Their Context API is what you're going to want, it pretty much does what is says on the tin. Works server-side and client-side (without requiring you to draw a map, like Google.)
GeoNames can also do this and allows up to 30K "credits" a day, different queries expend different credit amounts. The free service has highly variable performance, the paid service is more consistent. I've used them in the past, but don't much anymore because of the difficulty of automatically dealing with their data, which is more "pure" but less meaningful to most people.