  Master equations are probably the most fundamental equations for anyone
working in quantum optics in the presence of dissipation. In this context it is
then incredibly useful to have efficient ways of coding and simulating such
equations in the computer, and in this notes I try to introduce in a
comprehensive way how do I do so, focusing on Matlab, but making it general
enough so that it can be directly translated to any other language or software
of choice. I inherited most of my methods from Juan Jos\'e Garc\'ia-Ripoll
(whose numerical abilities I cannot praise enough), changing them here and
there to accommodate them to the way my (fairly limited) numerical brain works,
and to connect them as much as possible to how I understand the theory behind
them. At present, the notes focus on how to code master equations and find
their steady state, but I hope soon I will be able to update them with time
evolution methods, including how to deal with time-dependent master equations.
During the last 4 years I've tested these methods in various different
contexts, including circuit quantum electrodynamics, the laser problem, optical
parametric oscillators, and optomechanical systems. Comments and (constructive)
criticism are greatly welcome, and will be properly credited and acknowledged.
