Maths Concept: Draw line to follow mouse, with a radius limit
math,line,limit,conceptual,radius
Paraphrasing from my above comment: radius = 100; angle = atan2(mouse_position.y-center.y, mouse_position.x-center.x); if (distance(center, mouse_position) < radius){ line_position = mouse_position; } else{ line_position = center + Vector(radius*cos(angle), radius*sin(angle)); } ...
Binding C libraries on Python and Perl but reverse
python,c,web,converter,conceptual
Yes, you can. The term of art is "embedding," as in "embedded Python" or "embed a Python interpreter." Python has a document about it here: https://docs.python.org/2/extending/embedding.html - the general idea is you must use (at least a small part of) the Python C API to launch Python within a C...
Understanding the Dependencies of a Makefile (C++)
c++,c++11,makefile,dependencies,conceptual
Make doesn't really know anything about any particular programming language or tool, so it doesn't understand that C/C++ files depend on headers as well as source files. It just has rules of the form target: dependencies actions All it knows from this is that the file target depends on the...
GVariant , decompile or not
GVariant Database is the binary format used by gvdb. That file is compiled from XML files using glib-compile-schemas. I'm having trouble thinking of a situation where decompiling would be useful, which explains why I don't think anyone has written a tool to do it (if that is possible). Without knowing...
Android development with no screen
As mentioned, turning on USB debugging without the screen isn't possible. You can't enable USB debugging over USB for security reasons, so your only option would be to use hardware commands to put the device in firmware download mode (presumably it will have a way to do that), then load...
Why aren't method references singleton?
For instance methods, I don't think it would make sense for them to be cached. You'd have to cache one method per instance... which would either mean an extra field within the class associated with the method - one per public method, presumably, because the methods could be referenced from...
Resize openGL PBO's or recreate OGL context
Creating a new context is a fairly heavy weight operation, at least compared to most other things you would do when you use OpenGL. So unless you have a good reason why you need a new context, I would avoid it. Re-allocating the PBOs and objects is easy enough. As...
MySQL help figuring out structure of databases
Follow the directions here: http://docs.oracle.com/javase/tutorial/jdbc/basics/gettingstarted.html , for MySQL. Most RDBMSs, including MySQL, are implemented as servers to which your Java program connects using the JDBC interfaces. There are a few that have local files -- derby, sqlite, access -- but not in general. Basically, it goes like this: Java program...
R: Clustering customers based on similar product interests for an event
r,csv,hierarchical-clustering,euclidean-distance,conceptual
All answers were important, but @Ben video recommendation and @Samuel Tan advice on breaking the customers into grids, I found a good way to handle it. The video gave me a lot of insights about "noisy" variables in hierarchical clustering, and the grid recommendation helped me think on what the...
Conceptual Modelling - Is my drawing correct ?
model,uml,conceptual,3d-modelling,graph-modelling-language
Your model is missing association ends, which are very important. They confer semantics and multiplicities in both directions. An implementation model would be: |Monkey|--eatingMonkey[0..1]---------eatenBanana[0..*]--|Banana| That prevents the banana from being eaten by more than one Monkey. This is pidgin UML, so I hope you understand how to make a UML...
Why I must provide pointer and not SharedPtr into some methods of poco
c++,pointers,poco-libraries,conceptual
See discussion on the POCO Forum.
Understanding classes in java
Regarding: Hence I would have to instantiate some date first? Can I call an instance method without instantiating a "date" object of some kind? Correct. To call an instance method of Date, you must first create a Date object, which you are currently doing in your main method. Date today;...
Difference between 'this' and 'self' in programming languages
There is nothing special about the name self. It's the name preferred by convention by Pythonistas. The same goes for Java this, nothing special, just the name chosen by convention....
Concept: Trial & Full version in IOS today. (separate Apps, inapp purchases, Applestore rejection)
This is quite a common pattern, you just can't call your "trial" version "trial". Quite often such versions are called "light". To send the user to the app store to buy the full version you can use the SKStoreProductViewController to display the app store page for your full version directly...
Django: Using views to handle the logic of template tags?
django,architecture,views,conceptual,templatetags
In my opinion, the problem with template tags are: Too much abstraction. Challenging to test. Problems with performance What I suggest instead is: Create a function that generates the data, caches the data, handles permissions, anything else data related Write three more functions that render the data in HTML, JSON,...