Shown below is a published version (PDF format with appended graphs from output and command window) of the MATLAB code. The comments guide the reader on what is being computed and how to analyze it. The example case shown below utilizes piston links and sizes appropriate for system integration, hence the smooth sinusoidal movement curve of a piston. Below the code is an attached figure of a system with incorrect sizing.
The inflection/crossover alignment portion shows where the piston will receive additional friction from the system due to a change in inertia via sudden change in direction (e.g. when it reaches TDC or BDC).