I'm trying to develop a app with a teacher of mine to help students with some math subjects. The problem is that I'm stuck on how to make a proper beautiful XY graph with circles (such as x²+y²=R²). I'm pretty much a noobie in programming, but I'm just asking for some directions on how to do it.
I've tried chart libs such as Androidplot, MPAndroidchart etc, but as far as I could differ, they aren't made to deal with circles because of axis proportion issues (I ended up with elipses).
I already know some openGL (but not much) and I've heard about drawing with the Canvas. Which direction should I take? Or do anyone knows a graph lib that could solve my problem?
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I tried to find answer for my question, but I wasn't lucky. I have an Android app where I have thousands of points which have an altitude data and I want to draw that data in graph. What app is doing now is drawing graph data to ImageView. But I want to add zoom functionality, because when there are too many points that graph is too contracted.
I dont want to draw it to larger image and then downsample it, because it will take much memory - there can possible be many of these graphs. And I tried MPAndroidChart library to create that graph, but when there were thousands of points it drastically slowed down app.
I don't know what is the best to do. What do you think? I hope that this isn't a duplicate question and if you know that someone tried to solve this question, please let me know. Thnaks a lot.
This is complex stuff.
I can only recommand HelloCharts library that handles many things (including zoom): https://github.com/lecho/hellocharts-android
I am trying to create an android app which can recognize Billiard balls on a pool table in an image coming from the camera. What would be the best approach to do this?
We can assume that the camera and the pool table are in fixed positions, but there could be object other than the balls on the pool table.
I am currently looking into two possible solutions:
Vuforia SDK - Simple API for object tracking / recognition, but I couldn't find any information about ball/sphere shape tracking. They have Cylinder and Image target that could possibly be used somehow to track the balls.
OpenCV - Seems much richer and steeper learning curve in comparison with Vuforia, but there is some information about Billiard ball detection online (e.g. this, and this).
Are there any addition approaches for solving this problem? What would be the easiest working approach for this?
Thanks!
The balls are moving or not?
I've used SURF (and SFIT) they work great for arrested objects. Have a look to the documentation page there are also two questions you should see this and this. Than if you want to calculate the trajectory I've tried Pymecavideo that uses OpenCv maybe a look into the source code could be interesting for your work.
I'm trying to create an app that will tell a person what zone of a building they are in. I'm using bluetooth dongles to get an approximate location, as oppose to exact location, and show the user on a map whereabouts they are. I would like it just to highlight the zone they are in, instead of a specific location.
I can get my hands on a floor plan of the building I am using so I'm just wondering if there is an easy way to incorporate this into some kind of map with an existing API? I found a question here which states that they just use an overlay on the image to show a marker of where the person is. Would this be a bit easier?
This is for my final year project so I would like to have some sort of flashy map if possible but I'm not sure where to start looking or if it's possible.
I also found this question which gives a great variety of apps that implement and indoor map, but I don't think I can just take this small piece of functionality that I need out of them as they seem to be complete apps.
Any information would be a great help. Anyone with experience in this sort of thing please share your knowledge :)
It doesn't sound like it'd be too complicated to just write your own custom view for this. Draw the map image to the canvas. Then for the zone the user is in, draw another 'highlight' graphic on top of the map that you just drew.
If you're not sure how to do this, there's a rather basic guide on how to create your own drawable widgets which should point you in the right direction. There are plenty of examples on drawing images to the canvas, eg this one.
Is there anything like WhirlyGlobe for Android?
I just need to place a texture on a sphere that can be manipulated by the user. It must also be able to place overlays at various latitudes and longitudes.
I don't want to include whole 3D engines and I don't really want to code with bunches of arrays and GL specifics.
Are there any options or is OpenTK the best?
I started working on my own implementation: https://github.com/mattleibow/OpenGlobe
It is a bit rough and old, but I am hoping to work on this again sometime.
Just in case someone is interested...
I am developing an android app where I have two images named earth and sun. I want to rotate the earth around the sun depending upon the user's touch event. That means the user should rotate the earth image. How would I do this?
Find some resources (books, online tutorials, etc.) that will teach you about graphics programming on Android.
Take your first stab at writing the code for this project yourself.
If you get stuck, post a question that displays the code you have written, and describe the issue you are having with that code.