  After a brief introduction to the statistical description of data, these
lecture notes focus on quantum field theories as they emerge from lattice
models in the critical limit. For the simulation of these lattice models,
Markov chain Monte-Carlo methods are widely used. We discuss the heat bath and,
more modern, cluster algorithms. The Ising model is used as a concrete
illustration of important concepts such as correspondence between a theory of
branes and quantum field theory or the duality map between strong and weak
couplings. The notes then discuss the inclusion of gauge symmetries in lattice
models and, in particular, the continuum limit in which quantum Yang-Mills
theories arise.
