Why NemoMath?

NemoMath is a math-library for robotics and learning... so why don't you just use Eigen 2???

The answer is twofold:

1.: NemoMath takes care of shared ownership issues in robotics/learning applications and systems.

Use Eigen (or similar Libs) in something more complex than one method of spaghetti code and you need to think about two questions:
  • Who is responsible for deleting an object?
  • Who is allowed to modify an object (mutability) and when is a copy necessary?

The first thing that people usually come up with are smart-pointers like boost::shared_ptr. It solves the problem when to delete an object. But, it makes the mutability-issue even worse, since it is not transparent to const-correctness. There is always a danger that some other objects holds a smart pointer on your vector and modifies it. Also, you lose a lot of the original API convenience, such as mathematical operators, which are not directly usable through a smart-pointer.

NemoMath tackles these problem elegantly in the background by using
  • Highly efficient intrusive-counters on internal data-objects. Passing a nemo::MathVector is almost as efficient as passing a plain C-pointer.
  • Copy-on-write on all Vector and Matrix objects. You can pass them without expensive copying been performed. Once a write-operation takes place, the library takes care of a copy.

Due to these two features, working with nemo::MathVector and nemo::Matrix feels like using simple objects, with which you can do "value-based" programming.
Yet it avoids all the typical overhead. See source:/trunk/nemomath/examples/ExampleVector.cpp

2.: NemoMath goes far beyond linear algebra.

Ultra-flexible Functor API Convenient container data-structures