We report the design and implementation of a call-graph profiler for GNU Octave, a numerical computing platform. GNU Octave simplifies matrix computation for use in modeling or simulation. Our work provides a call-graph profiler, which is an improvement on the flat profiler. We elaborate design constraints of building a profiler for numerical computation, and benchmark the profiler by comparing it to the rudimentary timer start-stop (tic-toc) measurements, for a similar set of programs. The profiler code provides clean interfaces to internals of GNU Octave, for other (newer) profiling tools on GNU Octave.