Re: How to access an array using two different indexing schemes

[G. B. <nonlegitur@nmhp.invalid>]

Jerry <list_email@icloud.com> wrote:

> Your problem would also be solved by a sub-matrix capability which is
> apparently what you describe for PL/1. Of course Ada also lacks this
> capability along with matrix compositions, both of which Matlab excels at.

Except that these are different, higher level things.
A matrix or vector in R or in Matlab or in APL or in ...
is not at all the same thing as in Ada, physically.
The former are opaque objects, e.g. a stretch of storage 
associated with and “typed” by a dimension object,
giving meaning to runtime operations such as
“column 4” or “convert to 2x3”
Whereas an array in Ada is more like a bounded 
layout of typed data in storage. The Ada data structure 
can be used for implementing the higher level 
dimensioned objects mentioned.