v0.7.0

Modia v0.7.0

Diff since v0.6.1

Non-backwards compatible changes (basically, these changes are, erronously, in 0.6.1):

• Equations can only be defined with key equations and no other key
  (still, expressions can be associated with one variable, such as b = Var(:(2*a))).
  In versions 0.6.0 and before, equations could be associated with any key.

• The merge operator | appends the expression vectors of equations, so
  m1 | m2 basically appends the vector of m2.equations to the vector of m1.equations.
  In versions 0.6.0 and before, the merge operator did not handle equations specially,
  and therefore m1 | m2 replaced m1.equations by m2.equations.

• Parameter values in the code are now type cast to the type of the parameter value from the
  @instantiatedModel(..) call. The benefit is that access of parameter values in the code is type stable
  and operations with the parameter value are more efficient and at run-time no memory is allocated.
  Existing models can no longer be simulated, if parameter values provided via simulate!(.., merge=xx) are not
  type compatible to their definition. For example, an error is thrown if the @instantedModel(..) uses a Float64 value and the
  simulate!(.., merge=xx) uses a Measurement{Float64} value for the same parameter

• Operator buildModia3D(..) as used in Modia3D models is removed. Instead, the new constructor
  Model3D(..) must be used at the top level of a Modia3D definition. It is now possible to define
  several, independent multibody systems (currently, only one of them can have animation and animation export).

• Var(init=[...]) or Var(start=[..]) of FreeMotion joints must be defined as
  Var(init=SVector{3,Float64}(..)) or Var(start=SVector{3,Float64}(..)).
  Otherwise, errors occur during compilation.

Other changes

• Documentation (especially tutorial) adapted to the new version.

• Examples and test models (Modia/examples, Modia/tests) adapted to the new version, especially
  to the non-backwards compatible changes.

• For further changes of equation-based models, see the release notes of ModiaLang 0.11.0.

• For further changes of Modia3D models, see the release notes of Modia3D 0.9.0.

Closed issues:

• Modia.jl 0.6.1 instantiatemodel fails (#137)