statistical mechanics - Calculating temperature from molecular dynamics simulation

My understanding is that temperature is an inherently macroscopic quantity, but I've seen a number of people talk about calculating the temperature of ideal-gas simulations like this one. To take one example, in the final simulation here the author, a physicist, mentions calculating the pressure and temperature of the particles in his simulation.

Is it possible to define temperature for such a system, and to calculate it within a simulation? And how would one go about doing this?

Thanks