diagonalize

• diagonalise (non-Oxford British English)

From diagonal +‎ -ize.

diagonalize (third-person singular simple present diagonalizes, present participle diagonalizing, simple past and past participle diagonalized)

1. (mathematics, transitive) To convert a square matrix into a diagonal matrix by multiplying it by a second matrix and its inverse.
2. (cybernetics) To design variables such that design problems only bear upon subsets that are loosely coupled to others.
   • 2017, Andrew Pickering, “Ross Ashby”, in The Cybernetic Brain, University of Chicago Press, published 2010, →ISBN, page 159:

     And what we should do, therefore, is to diagonalize the variables—we should find some new design variables such that design problems only bear upon subsets of them that are loosely coupled to others, like the subsystems of ten lights in the example.