Modified the vector magnitude worklet to accept VecAll instead
of Vec3 and return Scalar. Modified the Magnitude() and Sqrt() functions
to return FloatDefault for all inputs except for Float64.
Perhaps we should modify other functions in Math.h and VectorAnalysis.h to
return float types for intergral arguments instead of integral types?
Change the VTKM_CONT_EXPORT to VTKM_CONT. (Likewise for EXEC and
EXEC_CONT.) Remove the inline from these macros so that they can be
applied to everything, including implementations in a library.
Because inline is not declared in these modifies, you have to add the
keyword to functions and methods where the implementation is not inlined
in the class.
Using v0+w*(v1-v0) can be numerically unstaqble due to floating point
arithmatic errors. Additionaly, the newer form also resolves type
conversion warnings.
