mathematics

What about create a design pattern directory with the most popular design patterns examples?
We can create some rules like: have to be an explanation about the design pattern, the structure and one real world example.
The directory can be:

(folder) Design Patterns
-- (folder) Abstract Factory
-- -- AbstractFactory.js
-- -- AbstractFactoryTest.js
-- -- REAME.md

I can send some :

If one uses the VisualizeError and FillColor options of RooAbsReal::plotOn(), for example like this:

using namespace RooFit;
model.plotOn(frame, VisualizeError(*r, 1), FillColor(kOrange));

You get a false warning:

WARNING:Plotting -- Fill color or style was set for plotting "model", 

IEEE 754 recommends (but does not require) a compound function, which is in the process of being standardized for C and C++; we should expose it in swift-numerics. The simplest, most literal translation of the operation into Swift would be:

extension RealFunctions {
  /// (1+x)ⁿ
  /// 
  /// Returns NaN if x < -1.
  static func compound(_ x: Self, _ n: Int) -> Self {
    // not

Start from the develop branch and add to examples/simple:

• igraph_assortativity.c, which calls the function igraph_assortativity (in /src/misc/mixing.c) with some graph and prints out the result,
• igraph_assortativity.out which contains the correct printed result.

Then, add the example to tests/CMakeLists.txt and to the docs of the function in /src/misc/mixing.c

For an example of a si