  A common theme in all the above areas is designing a dynamical system to
accomplish desired objectives, possibly in some predefined optimal way. Since
control theory advances the idea of suitably modifying the behavior of a
dynamical system, this paper explores the role of control theory in designing
efficient algorithms (or dynamical systems) related to problems surrounding the
optimization framework, including constrained optimization, optimization-based
control, and parameter estimation. This amalgamation of control theory with the
above-mentioned areas has been made possible by the recently introduced
paradigm of Passivity and Immersion (P\&I) based control. The generality and
working of P\&I, as compared to the existing approaches in control theory, are
best introduced through the example presented below.
