Structs
SmoothedParticles.AbstractParticle — TypeAbstractParticleAbstract supertype for smoothed particles. Any structure with AbstractParticle supertype is expected to:
- be mutable
 - have field 
x::RealVector(particle position) 
SmoothedParticles.ParticleField — TypeParticleField(sys::ParticleSystem, varS::Symbol)Creates an abstract array whose $n$-th element is the value of scalar varS of $n$-th particle in sys.
The indentity of $n$-th particle in ParticleSystem may change when particles are added or removed.
SmoothedParticles.ParticleSystem — TypeParticleSystem(T::Type, domain::Shape, h::Float64)Struct that contains all vital information about the simulation. The constructor specifies that:
- the simulation will use particles of type 
T <: AbstractParticle, - Particles outside of the 'domain' can be disregarded (and will be automatically removed).
 - Particles are considered neighbours if their distance is less than 
h. 
Please, do not make 'domain' unnecessarily large (has negative impact on performance).
SmoothedParticles.Shape — TypeShapeSupertype for geometrical shapes.