[Insight-developers] Best way to concatenate itk Arrays?

[Michael Stauffer (Circular Logic)]

Hi,

I need to concatenate itk Arrays (Transform::ParameterType objects,
actually) into a single new Array. Is it acceptable to directly use the
underlying public vnl_vector routines like data_block() and copy_out()
to do this efficiently? Or must I copy element-by-element using
Array::GetElement(). Or is there some other way I'm missing?

I could add an Insert method to Array that allows inserting of another
array at a given index, in order to avoid using the vnl_vector routines
directly.

This is part of the new CompositeTransform class. We're set-ing and
get-ing concatenated parameter arrays that hold the parameters for all
the constituent transforms in the composite class. We may have dozens of
transforms at once, so element-by-element copying will start to add up
over all the calls to get and set parameters made by the optimizer in
the registration process.

Cheers,
Michael