I have a simple mathprog program which is run on hundreds of data items of the same form (a 3-vector).

Ok, I understand. I assumed you were providing a general purpose module. Please ignore my hypercritical comments.

Solving your task using PDL::Opt::GLPK might be easier than you think. If you provided a few examples that shall be solved simultaneously, I could write you a sub that solves these using the PDL module. You wouldn't have to deal with PDL at all elsewhere.